ARM: dts: msm: update regulator nodes for sdmmagpie

Add PM8009 regulator nodes and update all SDMMAGPIE regulator
configuration as per AOP.
- update LDOA18 regulator to "XO_BUFFER" type regulator(only
supports enable/disable with constant output voltage).
- update min/max voltages of S1C, S8C, L1A, L2A and L3A.
- add refgen regulator.

Change-Id: I2857869b9e2f93ccefb4983228b21ed7caf8e547
Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>