ARM: davinci: board-dm646x-evm: set VPIF capture card name

VPIF capture driver expects card name to be set since it
uses it without checking for NULL. The commit which
introduced VPIF display and capture support added card
name only for display, not for capture.

Set it in platform data to probe driver successfully.

While at it, also fix the display card name to something more
appropriate.

Fixes: 85609c1c ("DaVinci: DM646x - platform changes for vpif capture and display drivers")
Signed-off-by: Sekhar Nori <nsekhar@ti.com>