ARM: shmobile: r8a7778: Fix pin control device address in DT

The PFC device is erroneously declared at address 0xfffc000 instead of
0xfffc0000. Fix it.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Tested-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>