Add smm_variable service provider

Adds an implementation of a service provider for the smm_variable
service. Accepts uefi variable requests and uses the
uefi_variable_store as the backend for storage.

Signed-off-by: Julian Hall <julian.hall@arm.com>
Change-Id: I050fc26c03b4d0098ccc303a293b8faeab488419
diff --git a/deployments/component-test/component-test.cmake b/deployments/component-test/component-test.cmake
index 1ffcb69..2fdc857 100644
--- a/deployments/component-test/component-test.cmake
+++ b/deployments/component-test/component-test.cmake
@@ -118,6 +118,7 @@
 		"components/service/test_runner/provider"
 		"components/service/test_runner/provider/serializer/packed-c"
 		"components/service/test_runner/provider/backend/null"
+		"components/service/smm_variable/provider"
 		"components/service/smm_variable/backend"
 		"components/service/smm_variable/backend/test"
 		"protocols/rpc/common/protobuf"