video: fbmem: assign bpp value for var_screeninfo

video: fbmem: assign bpp value for var_screeninfo

bits per pixel is not specified in few scenarios.
E.g.: Modes set through nvdisp_setmode.
In such cases, fbconsole fails during subsequent
operations. Hence assign bpp value from previous mode
if bpp is not set.

bug 200277699

Change-Id: I154ce70b9c67c0ca99b0efc71b2c0cf120b07ef3
Signed-off-by: Naveen Kumar S <nkumars@nvidia.com>
Reviewed-on: http://git-master/r/1492910
GVS: Gerrit_Virtual_Submit
Reviewed-by: Tow Wang <toww@nvidia.com>
Reviewed-by: Santosh Galma <galmar@nvidia.com>
Reviewed-by: Bibek Basu <bbasu@nvidia.com>