smc911x: fix 16-bit I/O operations

This patch fixes the following issues related to 16-bit support:
 - Remove unused 16-bit PXA DMA implementation.
 - Remove unused SMC_inw() and SMC_outw() functions.
 - Fix 16-bit SMC_outl to use writew() instead of writel().

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>