spi: Updates for v6.3

This has been a fairly quiet release for SPI, though it is likely that
the next release will have some big changes as there's some preparatory
work for multiple chip select support gone in - the rest of the code is
on the list but will need to be rebased onto -rc1.  Otherwise there's a couple
of new tunables for chip select timings, some new devices and smaller
device specific updates and fixes.

 - Support for configuring the hold and minimum inactive times for chip
 - Beginnings of support for supporting devices which have multiple chip
   selects on a single device.
 - Support for newer Broadcom HSSPI and Intel controllers, Silicon Labs
   EM3581 and SI3210.

There is a simple add/add conflict in MAINTAINERS with the I2C tree.
Merge remote-tracking branch 'spi/for-6.3' into spi-next