cfg/zynq: Rearrange and add some Zynq specific configs.

zynq-arch: Force on Optimize for size as there are run time issues if it
is left unset.
Move forced AEABI config to arch cfg file, so all-other.cfg file can be
removed as it was for debug purposes only.
debug: Add dependent DEBUG_LL config.

Signed-off-by: Sipke Vriend <sipke.vriend@xilinx.com>