spi: intel: Implement dirmap hooks

Currently the driver goes over the supported opcodes list each time
->exec_op() is called and finds the suitable for the given operation.
This consumes unnecessary amount of CPU cycles because the operation is
always the same. For this reason populate dirmap hooks for the driver so
that we cache the selected operation and then simply call it on each
read/write.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Link: https://lore.kernel.org/r/20220420104350.19510-1-mika.westerberg@linux.intel.com


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