memory: pl353-smc: fix compile test on !ARM_AMBA

memory: pl353-smc: fix compile test on !ARM_AMBA

The pl353-smc driver uses module_amba_driver so it has a build
dependency on CONFIG_ARM_AMBA:

    /usr/bin/arm-linux-gnueabi-ld: drivers/memory/pl353-smc.o: in function `pl353_smc_driver_init':
    pl353-smc.c:(.init.text+0x10): undefined reference to `amba_driver_register'

However it still can be compile tested on platforms other than ARM,
which in practice is limited to those selecting ARM_AMBA (so only
ARM64).

Fixes: ea0c0ad6b6eb ("memory: Enable compile testing for most of the drivers")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/20201029193357.389593-1-krzk@kernel.org