platform/surface: Add s2idle/hibernate fix for Surface Laptop 5

[wowitsjack]

Closes linux-surface/linux-surface#1782
Per request from @qzed in linux-surface/linux-surface#2011

Adds surface_s2idle_fix module to drivers/platform/surface/.

Problem

Intel INTC1055 pinctrl power-gating during s2idle corrupts pin 213's PADCFG0 register. The corruption fires a spurious SCI on GPE 0x52, which promotes to a full resume via acpi_any_gpe_status_set(). The system either never wakes (wakeup framework poisoned by pm_system_cancel_wakeup()) or wakes spuriously on every s2idle cycle.

Fix

The ACPI wakeup handler runs before acpi_ec_dispatch_gpe() in the s2idle wake decision path. The handler:

1. Repairs PADCFG corruption (full register comparison, not just RXINV)
2. Clears GPE 0x52 status so acpi_any_gpe_status_set() doesn't see it
3. Returns false (no full wake)

Lid-open detection is deferred to an LPS0 check() callback which reads RXSTATE directly and only calls pm_system_wakeup() if the lid is genuinely open.

Key design decisions

• GPE 0x52 masked during s2idle: VNN power-gating causes transient RXSTATE glitches that fire GPE 0x52 as SCI. Lid detection handled by 500ms poll timer reading RXSTATE directly.
• GPE unmask delayed to PM_POST_SUSPEND: Stale GPE status from lid state changes fires immediately on unmask during resume_early, causing false lid events to logind.
• Reference-counted GPE management: Uses acpi_enable_gpe/acpi_disable_gpe (not acpi_set_gpe) to maintain proper ACPI reference counting.
• Full PADCFG0 corruption detection: Compares entire register (minus volatile GPIORXSTATE) instead of just RXINV, catching all VNN corruption.
• 1ms GPIORXDIS toggle + 15s settling guard: Extended input buffer enable for reliable re-latching after PADCFG restore.

Additional layers

• Failsafe re-suspend with exponential backoff (2s/4s/8s/15s)
• RXSTATE polling for lid close detection
• Suspend-to-lock mode (converts lid-open suspend to lock+blank)
• Hibernate support with RTC time sync
• SW_LID input events for userspace lid policy

Testing

Tested on Surface Laptop 5 (i5-1245U), Ubuntu 25.10, kernel 6.18.7-surface-1. s2idle cycles, hibernate cycles, extended sleep (11h+), repeated lid open/close, rapid-wake VNN cycles with failsafe re-suspend.