ARM: msm: clean-up mach/io.h

Move msm specifics in mach/io.h to respective msm_iomap-*.h headers.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>