ACPI: Add missing prototype for non CONFIG_SUSPEND/CONFIG_X86 case

ACPI: Add missing prototype for non CONFIG_SUSPEND/CONFIG_X86 case

acpi_register_lps0_dev() and acpi_unregister_lps0_dev() may be used
in drivers that don't require CONFIG_SUSPEND or compile on !X86.

Add prototypes for those cases.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202502191627.fRgoBwcZ-lkp@intel.com/
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20250407183656.1503446-1-superm1@kernel.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>