spi: mt65xx: Move clock parent setting to remove clock disable gotos

spi: mt65xx: Move clock parent setting to remove clock disable gotos

Reparenting sel_clk to parent_clk can be done before enabling any of
spi_clk and spi_hclk. Move the call to clk_set_parent() for sel_clk
earlier, and call disable_unprepare() upon spi_clk prepare_enable()
failure to remove all clock disablement related gotos.
This commit is in preparation of a later cleanup.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20220407114428.167091-5-angelogioacchino.delregno@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>