drm/i915/pm: Do pci_restore_state() in switcheroo resume hook

drm/i915/pm: Do pci_restore_state() in switcheroo resume hook

Since this switcheroo garbage bypasses all the core pm we
have to manually manage the pci state. To that end add the
missing pci_restore_state() to the switcheroo resume hook.
We already have the pci_save_state() counterpart on the
suspend side.

Arguably none of this code should exist in the driver
in the first place, and instead the entire switcheroo
mechanism should be rewritten and properly integrated into
core pm code...

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Jouni Högander <jouni.hogander@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20250919185015.14561-5-ville.syrjala@linux.intel.com