Up to now the SPI alias was used as an index into an array defined in
the SPI driver to determine the SPI FIFO depth. Drop the dependency on
the SPI alias and specify the SPI FIFO depth directly into the SPI node.

exynos5420.dtsi defines the following aliases:
	spi0 = &spi_0;
	spi1 = &spi_1;
	spi2 = &spi_2;
spi-s3c64xx.c driver defines the following fifo_lvl_mask for the
"samsung,exynos4210-spi" compatible:
	.fifo_lvl_mask  = { 0x1ff, 0x7F, 0x7F },
Thus spi0 was considered having a 256 byte FIFO depth, and spi1 and spi2
having 64 byte FIFO depth each. Update device tree with these FIFO depths.
No functional change expected.
Signed-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20240216140449.2564625-5-tudor.ambarus@linaro.orgSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>