arm: print information about loaded UEFI images

If an exception occurs in a UEFI loaded image we need the start address of
the image to determine the relocation offset.

This patch adds the necessary lines after the registers in the crash dump.
A possible output would be:

UEFI image [0xbffe6000:0xbffe631f] pc=0x138 '/\snp.efi'

With the offset 0x138 we can now find the relevant instruction in the
disassembled 'snp.efi' binary.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>