spidev: Add Micron SPI NOR Authenta device compatible

Add compatible string for Micron SPI NOR Authenta device.

Signed-off-by: Shivamurthy Shastri <sshivamurthy@micron.com>
Link: https://lore.kernel.org/r/20210419204015.1769-1-sshivamurthy@micron.com


Signed-off-by: Mark Brown <broonie@kernel.org>