msm: watchdog: set up dump area from cpu 0

The secure side will not correctly set up CPU0's watchdog interrupt as
an FIQ if the scm_call is made from CPU1. So, always make this call from
CPU0.

CRs-Fixed: 340231
Change-Id: Ic2ef2338a2e7b263be62af8ae606c32869c0c273
Signed-off-by: Jeff Ohlstein <johlstei@codeaurora.org>