ASoC: rcar: Use && instead of & for boolean expressions

Sparse spits out the following warning:
	sound/soc/sh/rcar/gen.c:250:21: warning: dubious: x & !y

It does this because sometimes mixing boolean and bit-wise logic has not the
intended result. In this case we are fine, but replacing the bit-wise '&' with
the boolean '&&' silences the sparse warning. The generated code for both cases
is the same.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>