T-Deck fix: revert KB_POWERON changes

[mverch67]

The change in #2786 to disable the T-Deck's keyboard during screen blanking to save 20mAh power seems to have a negative side effect on the LoRa TX interrupt which leads to a reboot when sending mesh packets after the screen blanking.
This PR reverts the change in PowerFSM.cpp.

INFO  | ??:??:?? 201 [Screen] From Radio onread
INFO  | ??:??:?? 201 [Screen] getFromRadio=STATE_SEND_PACKETS
DEBUG | ??:??:?? 201 [Screen] encoding toPhone packet to phone variant=11, 12 bytes
INFO  | ??:??:?? 201 [Screen] From Radio onread
WARN  | ??:??:?? 201 [RadioIf] Can not send yet, busyTx
ERROR | ??:??:?? 201 [RadioIf] Hardware Failure! busyTx for more than 60s
ERROR | ??:??:?? 201 [RadioIf] NOTE! Recording critical error 8 at src/mesh/RadioLibInterface.cpp:88
INFO  | ??:??:?? 201 Rebooting

[20:46:07.013] Disconnected
[20:46:08.014] Warning: Could not open tty device (Permission denied)
[20:46:08.014] Waiting for tty device..
[20:46:09.016] Connected
��@INFO  | ??:??:?? 2 

//\ E S H T /\ S T / C

[github-actions]

🤖 Pull request artifacts

file	commit
pr2847-firmware-2.2.10.75e1e97.zip	75e1e97