ARM: OMAP: igep0020: Specify the VPLL2 regulator unconditionally

The supply is connected to the DSS DO-D5 pins and is thus needed for
both serial and parallel display interfaces on the igep0030 as well as
the igep0020.

If the igep0030 module isn't connected to a display, no DSI or DPI
display will be specified in board code, and the DSS driver won't enable
to VPLL2 regulator anyway.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Enric Balletbo i Serra <eballetbo@gmail.com>
Tested-by: Enric Balletbo i Serra <eballetbo@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>