[SCSI] bnx2i: Fix context mapping issue for architectures with PAGE_SIZE != 4096

5706/5708/5709 devices allow driver/user to set page size. By default it is
set to 4096.  Current drivers do not program this register based on
architecture type (e.g. x86 = 4K, IA64 = 16K) and by choice lets device use
the defaults. So while mapping connection context memory (doorebll registers),
driver has to match page size used by the device. Included change fixes the
issue we uncovered during IA64 testing

Signed-off-by: Anil Veerabhadrappa <anilgv@broadcom.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>