pinctrl: atlas7: adjust vip pin groups for atlas7

The vip low 8bit mode and vip high 8 bit mode pin groups had missed
3 pins:vip_vsync, vip_hsync and vip_pxclk. Without these 3 pins, the
vip could not work properly.
Now we add these 3 pins into these two pin groups.

Signed-off-by: Wei Chen <Wei.Chen@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>