msm: Add support for cache dumping

When caches become corrupted during particularly nasty
bugs, it can become next to impossible to determine
whether a crash was caused by cache corruption or just
pure software error. Add support for dumping both the
L1 and L2 to an allocated buffer for post-mortem analysis.

Change-Id: I48f7aa5b6d2dfd2192f6c54bb5ac39c1bec80303
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>