ASoC: cs35l56: Accept values greater than 0 as IRQ numbers

IRQ lookup functions such as those in ACPI can return error values when
an IRQ is not defined. The i2c core driver converts the error codes to a
value of 0 and the SPI bus driver passes them unaltered to client device
drivers.

The cs35l56 driver should only accept positive non-zero values as IRQ
numbers.

Signed-off-by: Simon Trimmer <simont@opensource.cirrus.com>
Fixes: 8a731fd37f8b ("ASoC: cs35l56: Move utility functions to shared file")
Link: https://msgid.link/r/20240617135338.82006-1-simont@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>