ARM: dts: msm: Add LCDB BST node for PM6150L and PM8150L

The driver requires all the 3 nodes (bst, ldo, ncp) defined
for a proper initialization sequence. Without any of them it
skips the device tree parsing and variables stay un-initialized
causing incorrect configuration.

Change-Id: I04064abccee0014d01042e60e7ccbb25ab226e75
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>