Merge tag 'omap-for-v3.16/prcm-signed' into omap-for-v3.16/tmp-merge-2014-05-19

PRCM changes for omaps. I ended up merging these with the
big endian changes because of the merge conflicts for read
and write operations. Via Paul Walmsley <paul@pwsan.com>:

Some OMAP PRCM cleanup patches.  These help prepare to convert the PRCM
code into drivers.

Basic build, boot, and PM test results are available here:

http://www.pwsan.com/omap/testlogs/prcm-cleanup-v3.16/20140515213244/