Add support for a new devicetree compatible string called
'amazon,alpine-apb-ssi', which is necessary for the Amazon Alpine spi
controller. 'amazon,alpine-dw-apb-ssi' is used in the dw spi driver if
specified in the devicetree.  Otherwise, fall back to driver default
behavior, i.e. original dw IP hw driver behavior.
Signed-off-by: NTalel Shenhar <talel@amazon.com>
Signed-off-by: NDavid Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: NMark Brown <broonie@kernel.org>