drivers: thermal: Add shared interrupt handler support to LMH DCVS

Add support for shared interrupt handler to LMH DCVS. It helps to
notify scheduler properly for target which has common LMH hardware
and different clock domains.

Ignore thermal zone register error in case if thermal zone is not
defined for the shared LMH DCVS instance.

Change-Id: I2f0aa3da4e5a1d032602dd7c1e595830c7883c4e
Signed-off-by: Manaf Meethalavalappu Pallikunhi <manafm@codeaurora.org>