efi_loader: define UpdateCapsule api

In this commit, skeleton functions for capsule-related API's are
added under CONFIG_EFI_UPDATE_CAPSULE configuration.
Detailed implementation for a specific capsule type will be added
in the succeeding patches.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig
index 1b983fe..1681b37 100644
--- a/lib/efi_loader/Kconfig
+++ b/lib/efi_loader/Kconfig
@@ -94,6 +94,17 @@
 	  Provide the SetTime() runtime service at boottime. This service
 	  can be used by an EFI application to adjust the real time clock.
 
+config EFI_HAVE_CAPSULE_SUPPORT
+	bool
+
+config EFI_RUNTIME_UPDATE_CAPSULE
+	bool "UpdateCapsule() runtime service"
+	default n
+	select EFI_HAVE_CAPSULE_SUPPORT
+	help
+	  Select this option if you want to use UpdateCapsule and
+	  QueryCapsuleCapabilities API's.
+
 config EFI_DEVICE_PATH_TO_TEXT
 	bool "Device path to text protocol"
 	default y