[media] OMAP_VOUT: Increase MAX_DISPLAYS to a larger value

[media] OMAP_VOUT: Increase MAX_DISPLAYS to a larger value

There is no limit to the number of displays that can registered with DSS2. The
current value of MAX_DISPLAYS is 3, set this to 10 so that the 'displays'
member of omap2video_device struct can store more omap_dss_device pointers.

This fixes a crash seen in omap_vout_probe when DSS2 registers for more than 3
displays.

Signed-off-by: Archit Taneja <archit@ti.com>
Acked-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>