ARM: arch-shmobile: Use multiple irq vectors for SDHI

This patch reverts "ARM: mach-shmobile: sh7372 SDHI vector merge" and
supplies 3 IRQ resources for each SDHI block.

Some blocks have a 4th IRQ, but this is used for DRM feathres
that I do not have access tot he documentation for and are almost
certainly tainted by licensing issues. So the 4th IRQ is not
hooked-up even if it exists.

Cc: Chris Ball <cjb@laptop.org>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>