regulator: correct name used in debug consumer regulator_get call

Call rdev_get_name() to obtain the name to use in the debug
consumer's regulator_get() call so that the debug consumer finds
the correct regulator when the name differs in the constraints
and desc structs.

Change-Id: Id6a47467cd118c89c8f58d1120381d4c64f8efee
CRs-Fixed: 1075693
Signed-off-by: David Collins <collinsd@codeaurora.org>