Platform: Change Musca-S1 SCC to Secure only

This commit changes the configuration of the Serial Configuration
Control, making it secure. The ioctl services are extended to
allow access to some SCC functions from the non-secure code.

Change-Id: I87f52d6a157652c85a3e3a94b63576479c9895d7
Signed-off-by: Gabor Toth <gabor.toth@arm.com>
12 files changed