Implement simple transmit power boost and override

hal/rtl8812a/rtl8812a_phycfg.c

@@ -14,17 +14,34 @@
  *****************************************************************************/
 #define _RTL8812A_PHYCFG_C_
 
-/* #include <drv_types.h> */
-
 #include <rtl8812a_hal.h>
 
-/*---------------------Define local function prototype-----------------------*/
+/* Manual Transmit Power Control 
+   The following options take values from 0 to 63, where:
+   0 - disable
+   1 - lowest transmit power the device can do
+   2 - highest transmit power the device can do
+   Note that these options may override your country's regulations about transmit power.
+   Setting the device to work at higher transmit powers most of the time may cause premature 
+   failure or damage by overheating. Make sure the device has enough airflow before you increase this.
+   It is currently unknown what these values translate to in dBm.
+*/
 
-/*----------------------------Function Body----------------------------------*/
+// Transmit Power Boost
+// This value is added to the device's calculation of transmit power index.
+// Useful if you want to keep power usage low while still boosting/decreasing transmit power.
+// Can take a negative value as well to reduce power.
+// Zero disables it. Default: 2, for a tiny boost.
+int transmit_power_boost = 2;
+// (ADVANCED) To know what transmit powers this device decides to use dynamically, see:
+// https://github.com/lwfinger/rtl8192ee/blob/42ad92dcc71cb15a62f8c39e50debe3a28566b5f/hal/phydm/rtl8192e/halhwimg8192e_rf.c#L1310
 
-/*
+// Transmit Power Override
- * 1. BB register R/W API
+// This value completely overrides the driver's calculations and uses only one value for all transmissions.
- *   */
+// Zero disables it. Default: 0
+int transmit_power_override = 0;
+
+/* Manual Transmit Power Control */
 
 u32
 PHY_QueryBBReg8812(