spi: dt-bindings: fsl-qspi: support SpacemiT K3

spi: dt-bindings: fsl-qspi: support SpacemiT K3

Add the SpacemiT K3 QSPI compatible to the fsl-qspi binding.

K3 and K1 use the same QSPI controller, so document the K3 compatible
with "spacemit,k1-qspi" as fallback.

Signed-off-by: Cody Kang <cody.kang.hk@outlook.com>
Signed-off-by: Zhengyu He <hezhy472013@gmail.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://patch.msgid.link/20260521-k3-pico-itx-qspi-v2-for-next-20260521-v2-1-52bce26e5fd8@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>