ASoC: ux500_msp_i2s: Fix devm_* and return code merge error

Some ux500_msp_i2s patches clashed with:

b18e93a4
ASoC: ux500_msp_i2s: better use devm functions and fix error return code

... leaving the driver uncompilable. This patch fixes the
issues encountered.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>