ACPI: x86: Drop quirk for HP Elitebook

There was a quirk in `acpi/x86/s2idle.c` for an HP Elitebook G9
platforms to force AMD GUID codepath instead of Microsoft codepath.

This was due to a bug with WCN6855 WLAN firmware interaction with
the system.

This bug is fixed by WCN6855 firmware:
WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.23

Remove the quirk as it's no longer necessary with this firmware.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/commit/?id=c7a57ef688f7d99d8338a5d8edddc8836ff0e6de
Tested-by: Anson Tsao <anson.tsao@amd.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>