The arm-trusted-firmware-sunxi package is only used by the Allwinner
A64, so only make it selectable for its subtarget sunxi/cortexa53.
Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
Acked-by: Hauke Mehrtens <hauke@hauke-m.de>
Reviewed-by: Jonas Gorski <jonas.gorski@gmail.com>