PS: Fix build when PS_ENCRYPTION is turned off

Fixes a typo in the code for no encryption. Also adds the dependency
of PS_ROLLBACK_PROTECTION on PS_ENCRYPTION to the check config.

Change-Id: I9f10c6d079b627f510f051ab2764f9fec8670f3e
Signed-off-by: Jamie Fox <jamie.fox@arm.com>
2 files changed