ARM: dts: msm: Add interrupt 231 to mpm bypass list for 8937

Interrupt 231 is blocking the idleXO shutdown. The change is to
add interrupt 231 to the bypass list to allow idleXO.

Change-Id: I62ee3863f2286f0fab540e7be039ed72c78e226d
Signed-off-by: Srinivas Rao L <lsrao@codeaurora.org>