msm: vidc: Handle mgen2maxi interrupt in video driver

Handle interrupt generated by mgen2maxi h/w and
avoid unknown interrupts storm which results in
target reset issues.

Change-Id: Ida24cb2dde15c9cd4a4c1d9ca336b1a4b662c4d1
Signed-off-by: Maheshwar Ajja <majja@codeaurora.org>
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>