spi: Updates for v5.1

A fairly quiet release for SPI, the biggest thing is the conversion to
use GPIO descriptors which is now 90% done but still needs some
stragglers converting.

 - Support for inter-word delays.
 - Conversion of the core and most drivers to use GPIO descriptors for
   GPIO controlled chip selects.
 - New drivers for NXP FlexSPI and QuadSPI, SiFive and Spreadtrum.
-----BEGIN PGP SIGNATURE-----

iQFHBAABCgAxFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAlx9WtETHGJyb29uaWVA
a2VybmVsLm9yZwAKCRAk1otyXVSH0DfrB/92O47HJfHg1xIgOp4BLzT8lA5zQEsy
a8ApcLVLvY6mSfbB/G7RosfoPwTc1eZP5Q2BqzQOBIO+507ao4AcASARmkTwjwkC
eRUJ/THkGyGurs8POtnc5YJlHsT1t743QpqlUNekt+NqognlkPccgc5bNgixfuPD
eVSwVC85SKP3gCpAjVb6FFFmlWr8AKdlgx+41h9QpMNG/85H6xgo4C4Wlajt42/E
wNx+WXzlPyzB5Lc3IGPeF/I/Hu/Ta3hUZLTVpWi5ubM8p4SYGmMZ9l8sURPCz1pK
UMZFpJxx8DWwkj2F/FkoLasfiRqUHIP9K7NfKF0u2xdNbhEk1GA3NAG0
=ctKG
-----END PGP SIGNATURE-----
Merge branch 'spi-5.1' into spi-next