mtd: spi-nor: update read capabilities for w25q64 and s25fl064k

mtd: spi-nor: update read capabilities for w25q64 and s25fl064k

Both w25q64 and s25fl064k nor flash support QUAD and DUAL read
command, hence update the same in flash_info table.

This is tested on Broadcom Stingray SoC (bcm958742t).

s25fl064k and w25q64 share the same JEDEC ID. The search alg will
return the first hit, so s25fl064k even for the winbond parts. We
should differentiate between these flashes, but it's not in the
scope of this patch. Related discussion at:
Link: https://lore.kernel.org/patchwork/patch/628090/
Signed-off-by: Rayagonda Kokatanur <rayagonda.kokatanur@broadcom.com>
Link: https://lore.kernel.org/r/20200529071655.739-1-rayagonda.kokatanur@broadcom.com
[tudor.ambarus@microchip.com: Update commit message and indicate that
s25fl064k and w25q64 share the same JEDEC ID]
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>