powerpc/4xx: Necessary fixes to PCI for 4GB RAM size

The declaration of total_memory removed.  Now including <mm/mmu_decl.h>
instead.  Since total_memory is a phys_addr_t which is 64-bit on 44x and
is_power_of_2() works with u32 so I just inlined (size & (size-1)) != 0
instead.

Also this patch fixes default initialization: res->end should be 0x7fffffff
not 0x80000000.

Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Acked-by: Stefan Roese <sr@denx.de>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>