ACPI: silence ia64 build warning
ACPI: silence ia64 build warning

When building sim_defconfig, which does not define CONFIG_ACPI
arch/ia64/kernel/acpi.c:71: warning: 'acpi_madt_rev' defined but not used

really acpi.c should not be built when CONFIG_ACPI=n...

Signed-off-by: Len Brown <b060cfa1096cc6e8be83699ddb4ed8a77dd63af5@intel.com>

TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs