irq_of_parse_and_map() returns 0 on error, not NO_IRQ.

Fix the following xtensa:allmodconfig build error.

sound/soc/fsl/fsl_ssi.c:705:26: error: 'NO_IRQ' undeclared (first use in this function)
make[4]: *** [sound/soc/fsl/fsl_ssi.o] Error 1

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Grant Likely <grant.likely@linaro.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Mark Brown <broonie@linaro.org>