[ARM] 3414/1: ep93xx: reset ethernet controller before uncompressing

Patch from Lennert Buytenhek

The Redboot version that cirrus supplies for the cirrus ep93xx doesn't
turn off DMA from the ethernet MAC before jumping to linux, which means
that we might end up with bits of RX status and packet data scribbled
over the uncompressed kernel image.

Work around this by resetting the ethernet MAC before we uncompress.

We don't usually work around bootloader bugs, but considering that the
large majority of ep93xx boards out there have this problem, I figured
this it was justified in this case.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>