ASoC: fsl_ssi: let check zero instead of check NO_IRQ

NO_IRQ may be defined as '(unsigned int) -1' in some architectures
(arm, sh ...), and either may not be defined in some architectures
which can enable SND_SOC_FSL_SSI (e.g. allmodconfig for arc).

When irq_of_parse_and_map() fails, it will always return 0, so need
check zero instead of NO_IRQ, or will cause compiling issue or run
time bug in some architectures.

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Mark Brown <broonie@linaro.org>