arm64: compat: add syscall table entries for new syscalls

There have been a number of new syscalls introduced to arch/arm/ since
the compat layer was implemented for arm64, so add pointers to the
relevant functions to the compat syscall table.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>