ARM: dts: msm: Fix IPC interrupt configuration for msmcobalt

IPC interrupt register address has changed in msmcobalt. Update the
Device Tree with the concerned configuration.

Change-Id: If99de2f12f112a5fdd09863bbe974d482ceee20b
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@codeaurora.org>