ARM: decompressor: move GOT into .data for EFI enabled builds

We will be running the decompressor in place after a future patch,
instead of copying it around first. This means we no longer have to
disable and re-enable the MMU and caches either. However, this means
we will be loaded with the restricted permissions set by the UEFI
firmware, which means that we have to move the GOT table into the
data section in order for the contents to be writable by the code
itself.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>