smc911x: introduce platform data flags

This patch adds a new header file for platform data information
together with code that adds run time bus width and irq flag support.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>