ARM: msm: avoid calling debug_ll_addr on !MMU

MSM7X00A has an open-coded version of debug_ll_io_init so it
can use MT_DEVICE_NONSHARED as required by the platform.

However, this fails to build on no-MMU kernels because the
debug_ll_addr function is not available. Since the iotable_init
function doesn't actually do anyting in this configuration,
we can simply get away by enclosing the broken function call
in an #ifdef, which seems to be the least ugly workaround.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>