macsmc-input: skip spurious BTN_TOUCHID events on s2idle entry

[areofyl]

The SMC fires a spurious BTN_TOUCHID press+release within ~1ms of entering s2idle, which triggers pm_wakeup_dev_event and immediately wakes the system back up.

This patch skips the first 2 button events after pm_prepare. The counter resets on pm_complete so normal button handling is restored after resume.

Kernel log showing the spurious events (stock fairydust, no patch):

Jul 03 17:07:51 nimbus kernel: PM: suspend entry (s2idle)
Jul 03 17:07:52 nimbus kernel: macsmc 23e400000.smc: RTKit: syslog message: apComms.cpp:354: SMC HID Event: 01 06 01
Jul 03 17:07:52 nimbus kernel: macsmc 23e400000.smc: RTKit: syslog message: apComms.cpp:354: SMC HID Event: 01 06 00
Jul 03 17:07:52 nimbus kernel: PM: suspend exit

01 06 01 / 01 06 00 = BTN_TOUCHID press/release. This pattern repeats on every suspend attempt.

Tested on M1 MacBook Air (J313), fairydust 6.18.10.