ARM: shmobile: r8a7790: HSCIF support

Adds support for HSCIF0 and HSCIF1 on the r8a7790.

Signed-off-by: Ulrich Hecht <ulrich.hecht@gmail.com>
[ horms+renesas@verge.net.au this is the setup-r8a7790.c
  which I somehow miss-applied as part of another patch.
  The clock-r8a7790.c portion of this patch has already been merged. ]
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>