ARM: shmobile: ag5evm, ap4: Named SDHI IRQ sources

This allows specific (non-multiplexed) IRQ handlers to be used.

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