spi: mt7621: Fix an error message in mt7621_spi_probe()

spi: mt7621: Fix an error message in mt7621_spi_probe()

'status' is known to be 0 at this point. The expected error code is
PTR_ERR(clk).

Switch to dev_err_probe() in order to display the expected error code (in a
human readable way).
This also filters -EPROBE_DEFER cases, should it happen.

Fixes: 7f699088bda3 ("staging: mt7621-spi: add mt7621 support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Link: https://lore.kernel.org/r/928f3fb507d53ba0774df27cea0bbba4b055993b.1661599671.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Mark Brown <broonie@kernel.org>