regulator: add support to disable regualtor consumer node from DT

regulator: add support to disable regualtor consumer node from DT

Sometimes it is require to disable consumer list for some of the board
configuration from top level DTS file when using the common power tree
file across different boards/configuration.

Add support to have status property in the condumer node to ignore the
consumer supply from DT.

Change-Id: I1a42a1feaf0ae816833d43dffd1b1da29eb09d33
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/385002