plat/arm: Always allow ARM_LINUX_KERNEL_AS_BL33
plat/arm: Always allow ARM_LINUX_KERNEL_AS_BL33

At the moment we have the somewhat artifical limitation of
ARM_LINUX_KERNEL_AS_BL33 only being used together with RESET_TO_BL31.

However there does not seem to be a good technical reason for that,
it was probably just to differentate between two different boot flows.

Move the initial register setup for ARM_LINUX_KERNEL_AS_BL33 out of the
RESET_TO_BL31 #ifdef, so that we initialise the registers in any case.

This allows to use a preloaded kernel image when using BL1 and FIP.

Change-Id: I832df272d3829f077661f4ee6d3dd9a276a0118f
Signed-off-by: Andre Przywara <94eb15b8f54b8e37c3f8d338296201be47dc5c3e@arm.com>

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware