The HABv4 functions need access a part of the ROM which is
located in the zero page. This must be done early, before the
MMU has been configured and the zero page has been set to faulting.
The HAB functions currently use cpu_is_imxxy(). At the stage where
HAB is called the i.MX CPU type variable is not yet initialized,
so this code only works when only one i.MX type is enabled and
cpu_is_imxxy() are compile time constants.

To fix HAB support when more than one i.MX type is enabled make the
HAB status function SoC specific so that we can drop the use of
cpu_is_imxxy().

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>