vmalloc is used by ioremap() to get regions for
remapping I/O space.  To feed these regions back
into a __get_free_pages() type memory allocator,
they are expected to have more alignment than 
get_vm_area() proves.  So add additional alignment
constraints for VM_IOREMAP.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>