Provide separate interrupt handlers which may be used by platforms where
SDHI has three interrupt sources.

This patch also removes the commented-out handling of CRC and other errors.

Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
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>