virt_to_abs() is just a wrapper around __pa(), use __pa() directly.

We should be including <asm/page.h> to get __pa(). abs_addr.h will be
removed shortly so drop that.

We were getting of.h via abs_addr.h so we need to include that directly.

Having done all that, clean up the ordering of the includes.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Seth Jennings <sjenning@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>