App: Remove MSPLIM setup in test main function

MSPLIM is typically setup in the startup file.

This removes the requirement on linker scripts with specific symbol names.

Signed-off-by: Robert Rostohar <Robert.Rostohar@arm.com>
Change-Id: I6b4a350a1f7a5ae7c6f7542574c453df61febfac
1 file changed