esoc: Add snapshot of esoc driver

This is a snapshot of the esoc driver as of msm-4.4 commit <9d5748a>
(Merge "ARM: dts: msm: disable wdog wakeup on msm8996 vplatform").
The change also removes the support for older modems which are no
longer used.

Change-Id: I879768a3c56c986e66371700c062f3fa41448af7
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>