spi: s3c64xx: get rid of the OF alias ID dependency

Compatibles that set ``port_conf->{rx, tx}_fifomask`` are now safe to
get rid of the OF alias ID dependency. Let the driver probe even without
the alias for these.

With this we also protect the FIFO_LVL_MASK calls from
s3c64xx_spi_set_fifomask().

Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://msgid.link/r/20240216070555.2483977-10-tudor.ambarus@linaro.org


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