S4 suspend to disk will disable GPE's permanently
because acpi_gpe_sleep_prepare() does not have
a counterpart at resume time. Thus, those devices
became unavailable for wakeup from subsequent
S3 suspend-to-ram.
Here acpi_gpe_sleep_prepare() is removed, and upon suspend
acpi_enable_wakeup_device() gets its functionality.
Upon resume, acpi_disable_wakeup_device() restores the state.