[SPARC32]: Revert IOMAP change eb98129e

Breakage noted by Al Viro.

It breaks non-PCI builds, it's probably better to have a more
direct implementation on sparc32, and which driver actually
needs this is still questionable.

We can resolve this in 2.6.15

Signed-off-by: David S. Miller <davem@davemloft.net>