spi: bcm-qspi: Clean up 7425, 7429, and 7435 settings

The Broadcom QSPI driver now falls back to no MSPI_DEV support as the
default setting in the generic compatible string, explicit settings for
STB chips 7425, 7429, and 7435 can be removed.

Signed-off-by: Ray Jui <ray.jui@broadcom.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20200910152539.45584-4-ray.jui@broadcom.com


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