ASoC: mchp-spdifrx: fix return value in case completion times out

wait_for_completion_interruptible_timeout() returns 0 in case of
timeout. Check this into account when returning from function.

Fixes: ef265c55 ("ASoC: mchp-spdifrx: add driver for SPDIF RX")
Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/20230130120647.638049-3-claudiu.beznea@microchip.com


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