Make add_components CMake function reentrant

Change the scope of the internally used TGT variable from global
(cached) to local, allowing add_components calls on multiple levels.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I48f4000d6157e7b3c572b5c1b0645ee1d0b7a24a
1 file changed