mtd: spi-nor: Add Micron MT25QU02 support

Add support for a new Micron 2Gb Flash memory part.
Datasheet is available: mt25q_qlkt_l_02g_cbb_0.pdf

Testing was done on a Stratix10 SoCFPGA Development Kit.

Reported-by: Sujith Chidurala <sujith.chakra.chidurala@intel.com>
Tested-by: Paul Kim <paul.kim@intel.com>
Signed-off-by: Thor Thayer <thor.thayer@linux.intel.com>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>