t-beam supreme: PMU and i2c fixes

Fixed i2c (Wire) init issue by defining pins in platformio
Added an i2c scanning function for debug
Corrected the pmu power up sequence

variants/lilygo_tbeam_supreme_SX1262/platformio.ini

@@ -6,6 +6,8 @@ build_flags =
   -I variants/lilygo_tbeam_supreme_SX1262
   -D LORA_TX_POWER=22
   -D P_LORA_TX_LED=6
+  -D PIN_BOARD_SDA=17
+  -D PIN_BOARD_SCL=18
   -D RADIO_CLASS=CustomSX1262
   -D WRAPPER_CLASS=CustomSX1262Wrapper
   ;-D DISPLAY_CLASS=SSD1306Display      ;Needs to be modified for SH1106