arm-trusted-firmware-mediatek: fix PKG_MIRROR_HASH
Instead of using the hash of the Github-generated tarball use the
hash of the tarball generated by the OpenWrt build system (in this
case they are different, unfortunately).
Reported-by: Chen Minqiang <[email protected]>
Fixes: 07dbeb430e ("arm-trusted-firmware-mediatek: update to sources of 2023-07-24")
Signed-off-by: Daniel Golle <[email protected]>