msm: copper: Fix casing of dts names

The hex offsets that are part of node names in the DTS are required to
use lowercase hex characters.  By convention, the constants used
within the code are also in lower case.  Fix inconsistent casing, and
always use lower case.

Change-Id: I86e096c5aebb9011a5c12a4a2d558dedee5eb09a
Signed-off-by: David Brown <davidb@codeaurora.org>