ARM: dts: msm: Add PM660 configuration support

Add the PM660 configuration files for 8909w + PM660
platform. Delete all the earlier regulator references
of PM8909, they will be replaced with the PM660
regulator based on the platform power-grid.

CRs-Fixed: 2037603
Change-Id: Ic69608e80edd6f8952c59018a8f71dcb2076f89b
Signed-off-by: Ankit Sharma <ansharma@codeaurora.org>