Most of the ARM SoCs have small SRAM memory used for various purposes
that require faster access to data compared to normal DDR.

This patch enables the Generic on-chip SRAM driver on ARM64.

Cc: Kevin Hilman <khilman@kernel.org>
Cc: Olof Johansson <olof@lixom.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>