[ACPI] delete CONFIG_ACPI_BOOT

it has been a synonym for CONFIG_ACPI since 2.6.12

Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/include/asm-x86_64/mpspec.h b/include/asm-x86_64/mpspec.h
index 331f6a3..f267e10 100644
--- a/include/asm-x86_64/mpspec.h
+++ b/include/asm-x86_64/mpspec.h
@@ -179,7 +179,7 @@
 extern unsigned long mp_lapic_addr;
 extern int pic_mode;
 
-#ifdef CONFIG_ACPI_BOOT
+#ifdef CONFIG_ACPI
 extern void mp_register_lapic (u8 id, u8 enabled);
 extern void mp_register_lapic_address (u64 address);