spi: mediatek: move devm_spi_register_master position

This patch move devm_spi_register_master to the end of mtk_spi_probe.
If slaves call spi_sync in there probe function, master should have probe done.

Signed-off-by: Mason Zhang <Mason.Zhang@mediatek.com>
Link: https://lore.kernel.org/r/20210713114247.1536-1-mason.zhang@mediatek.com


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