fix(ras): do not put RAS check before esb macro

fix(ras): do not put RAS check before esb macro

Macro esb used in TF-A executes the instruction "esb" and is kept under
RAS_EXTENSION macro. RAS_EXTENSION, as it stands today, is only enabled
for platforms which wants RAS errors to be handled in Firmware while esb
instruction is available when RAS architecture feature is present
irrespective of its handling.
Currently TF-A does not have mechanism to detect whether RAS is present
or not in HW, define this macro unconditionally.

Its harmless for non-RAS cores as this instruction executes as NOP.

Signed-off-by: Manish Pandey <manish.pandey2@arm.com>
Change-Id: I556f2bcf5669c378bda05909525a0a4f96c7b336