SCR_EL3 is the control register for setting the security state

SCR_EL3 is the control register for setting the security state
modified the comment which can mislead.

The "ldr r0, [r1]" is overrided with a immediate "mov ro, #3"
instruction. This mov instruction will over write the contents
of the ro register. So replacing 'mov' by 'orr' instruction would
prevent to override the original value.

This patch assumes mov is the right instruction to be retained

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Girish K S <ks.giri@samsung.com>
Signed-off-by: Olivier Martin <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14606 6f19259b-4bc3-4df7-8a09-765794883524