ACPI: #define acpi_disabled 1 for CONFIG_ACPI=n

SFI will need to test acpi_disabled no matter
the value of CONFIG_ACPI.
Signed-off-by: Len Brown <len.brown@intel.com>

arch/x86/include/asm/acpi.h

@@ -144,6 +144,7 @@ static inline unsigned int acpi_processor_cstate_check(unsigned int max_cstate)
 
 #else /* !CONFIG_ACPI */
 
+#define acpi_disabled 1
 #define acpi_lapic 0
 #define acpi_ioapic 0
 static inline void acpi_noirq_set(void) { }