When ARM TF executes in AArch32 state, the NS version of SCTLR
is not being set during warmboot flow. This results in secondary
CPUs entering the Non-secure world with the default reset value
in SCTLR.

This patch explicitly sets the value of the NS version of SCTLR
during the warmboot flow rather than relying on the h/w.

Change-Id: I86bf52b6294baae0a5bd8af0cd0358cc4f55c416
Signed-off-by: David Cunado <david.cunado@arm.com>