Mention the official intel_rapl driver

On systems where the EC doesn't reset the values
(ex: ASUS Zenbook UX430UNR), it is probably prefered to use the
official intel_rapl driver.

README.md

@@ -3,6 +3,46 @@ This tool was originally developed to fix Linux CPU throttling issues affecting
 
 The CPU package power limit (PL1/2) is forced to a value of **44 W** (29 W on battery) and the temperature trip point to **95 'C** (85 'C on battery) by overriding default values in MSR and MCHBAR every 5 seconds (30 on battery) to block the Embedded Controller from resetting these values to default.
 
+On systems where the EC doesn't reset the values (ex: ASUS Zenbook UX430UNR), the power limit can be altered by using the official intel_rapl driver (note: [5.3](https://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux.git/commit/drivers/thermal/intel/int340x_thermal/processor_thermal_device.c?h=for-5.4&id=555c45fe0d04bd817e245a125d242b6a86af4593) or newer is required, if you want to change the MCHBAR values):
+```
+# MSR
+# PL1
+echo 44000000 | sudo tee /sys/devices/virtual/powercap/intel-rapl/intel-rapl:0/constraint_0_power_limit_uw # 44 watt
+echo 28000000 | sudo tee /sys/devices/virtual/powercap/intel-rapl/intel-rapl:0/constraint_0_time_window_us # 28 sec
+# PL2
+echo 44000000 | /sys/devices/virtual/powercap/intel-rapl/intel-rapl:0/constraint_1_power_limit_uw # 44 watt
+echo 2440 | /sys/devices/virtual/powercap/intel-rapl/intel-rapl:0/constraint_1_time_window_us # 0.00244 sec
+
+# MCHBAR
+# PL1
+echo 44000000 | sudo tee /sys/devices/virtual/powercap/intel-rapl-mmio/intel-rapl-mmio:0/constraint_0_power_limit_uw # 44 watt
+# ^ Only required change on a ASUS Zenbook UX430UNR
+echo 28000000 | sudo tee /sys/devices/virtual/powercap/intel-rapl-mmio/intel-rapl-mmio:0/constraint_0_time_window_us # 28 sec
+# PL2
+echo 44000000 | sudo tee /sys/devices/virtual/powercap/intel-rapl-mmio/intel-rapl-mmio:0/constraint_1_power_limit_uw # 44 watt
+echo 2440 | sudo tee /sys/devices/virtual/powercap/intel-rapl-mmio/intel-rapl-mmio:0/constraint_1_time_window_us # 0.00244 sec
+```
+If you want to change the values automatic on boot you can use [systemd-tmpfiles](https://www.freedesktop.org/software/systemd/man/tmpfiles.d.html):
+```
+# /etc/tmpfiles.d/power_limit.conf
+# MSR
+# PL1
+w /sys/devices/virtual/powercap/intel-rapl/intel-rapl:0/constraint_0_power_limit_uw - - - - 44000000
+w /sys/devices/virtual/powercap/intel-rapl/intel-rapl:0/constraint_0_time_window_us - - - - 28000000
+# PL2
+w /sys/devices/virtual/powercap/intel-rapl/intel-rapl:0/constraint_1_power_limit_uw - - - - 44000000
+w /sys/devices/virtual/powercap/intel-rapl/intel-rapl:0/constraint_1_time_window_us - - - - 2440
+
+# MCHBAR
+# PL1
+w /sys/devices/virtual/powercap/intel-rapl-mmio/intel-rapl-mmio:0/constraint_0_power_limit_uw - - - - 44000000
+# ^ Only required change on a ASUS Zenbook UX430UNR
+w /sys/devices/virtual/powercap/intel-rapl-mmio/intel-rapl-mmio:0/constraint_0_time_window_us - - - - 28000000
+# PL2
+w /sys/devices/virtual/powercap/intel-rapl-mmio/intel-rapl-mmio:0/constraint_1_power_limit_uw - - - - 44000000
+w /sys/devices/virtual/powercap/intel-rapl-mmio/intel-rapl-mmio:0/constraint_1_time_window_us - - - - 2440
+```
+
 ### Tested hardware
 Other users have confirmed that the tool is also working for these laptops:
 - Lenovo T480, T480s, X1C5, X1C6, T580, L480, T470, X280, ThinkPad Anniversary Edition 25, E590 w/ RX 550X, P43s