MIPS: xburst: fix broken access to global_data

Fix access to global_data which is broken since commits:

commit 035cbe99
Author: Simon Glass <sjg@chromium.org>
Date:   Thu Dec 13 20:49:08 2012 +0000

    mips: Move per_clk and dev_clk to arch_global_data

    Move these field into arch_global_data and tidy up. The other
    CONFIG_JZSOC fields are used by various architectures, so just remove
    the #ifdef bracketing for these.

Signed-off-by: Simon Glass <sjg@chromium.org>

commit 582601da
Author: Simon Glass <sjg@chromium.org>
Date:   Thu Dec 13 20:48:35 2012 +0000

    arm: Move lastinc to arch_global_data

    Move this field into arch_global_data and tidy up.

Signed-off-by: Simon Glass <sjg@chromium.org>

commit 66ee6923
Author: Simon Glass <sjg@chromium.org>
Date:   Thu Dec 13 20:48:34 2012 +0000

    arm: Move tbl to arch_global_data

    Move this field into arch_global_data and tidy up.

Signed-off-by: Simon Glass <sjg@chromium.org>

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Xiangfu Liu <xiangfu@openmobilefree.net>