ARM: shmobile: APE6EVM PFC support

Start using the r8a73a4 PFC on the APE6EVM board
and configure the SCIFA0 console signals in the
PFC via PINCTRL.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>