drivers/qe: Add more SNUM number for QE

Some QE chips like 8569 need more SNUM numbers for supporting 4 UECs in RGMII-
1000 mode.

Signed-off-by: Haiying Wang <Haiying.Wang@freescale.com>
Acked-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>