ARM: shmobile: r8a7740: fixup: MSEL1CR 7bit control

MSEL1CR 7bit selects IRQ7 source pin which was
VBUS pin or A21/MSIOF0_RSYNC/MSIOF1_TSYNC pin.
But current pfc-r8a7740 MSEL1CR 7bit setting was wrong.
This patch fix it up

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>