[SX126x] Fix upper power range in doxygen #1593

Job	Run time
esp-build	3m 50s
arduino:avr:mega	8m 23s
rpi-build	1m 40s
arduino:mbed:nano33ble	2m 16s
arduino:mbed:envie_m4	2m 16s
rpi-pico-build	50s
arduino:megaavr:uno2018	1m 57s
tock-build	1m 29s
arduino:sam:arduino_due_x	2m 24s
arduino:samd:arduino_zero_native	2m 59s
adafruit:samd:adafruit_feather_m0	2m 12s
adafruit:nrf52:feather52832	2m 12s
esp32:esp32:esp32	2m 15s
esp8266:esp8266:generic	4m 36s
STMicroelectronics:stm32:GenF3:pnum=BLACKPILL_F303CC	2m 30s
STMicroelectronics:stm32:Nucleo_64:pnum=NUCLEO_WL55JC1	2m 6s
stm32duino:STM32F1:mapleMini	4m 27s
MegaCoreX:megaavr:4809	2m 15s
arduino:mbed_rp2040:pico	2m 10s
rp2040:rp2040:rpipico	2m 15s
CubeCell:CubeCell:CubeCell-Board	2m 18s
MegaCore:avr:1281	2m 26s
teensy:avr:teensy41	5m 8s
arduino:renesas_uno:minima	2m 26s
rpi-test	13s
	1h 7m 33s

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