IB: Replace ib_umem page_size by page_shift

Size of pages are held by struct ib_umem in page_size field.

It is better to store it as an exponent, because page size by nature
is always power-of-two and used as a factor, divisor or ilog2's argument.

The conversion of page_size to be page_shift allows to have portable
code and avoid following error while compiling on ARM:

  ERROR: "__aeabi_uldivmod" [drivers/infiniband/core/ib_core.ko] undefined!

CC: Selvin Xavier <selvin.xavier@broadcom.com>
CC: Steve Wise <swise@chelsio.com>
CC: Lijun Ou <oulijun@huawei.com>
CC: Shiraz Saleem <shiraz.saleem@intel.com>
CC: Adit Ranadive <aditr@vmware.com>
CC: Dennis Dalessandro <dennis.dalessandro@intel.com>
CC: Ram Amrani <Ram.Amrani@Cavium.com>
Signed-off-by: Artemy Kovalyov <artemyko@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Acked-by: Ram Amrani <Ram.Amrani@cavium.com>
Acked-by: Shiraz Saleem <shiraz.saleem@intel.com>
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Acked-by: Adit Ranadive <aditr@vmware.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/hw/nes/nes_verbs.c

@@ -2165,9 +2165,9 @@ static struct ib_mr *nes_reg_user_mr(struct ib_pd *pd, u64 start, u64 length,
 	}
 
 	nes_debug(NES_DBG_MR, "User base = 0x%lX, Virt base = 0x%lX, length = %u,"
-			" offset = %u, page size = %u.\n",
+			" offset = %u, page size = %lu.\n",
 			(unsigned long int)start, (unsigned long int)virt, (u32)length,
-			ib_umem_offset(region), region->page_size);
+			ib_umem_offset(region), BIT(region->page_shift));
 
 	skip_pages = ((u32)ib_umem_offset(region)) >> 12;