ASoC: tlv320aic3x: Fix codec pll configure bug

In sound/soc/codecs/tlv320aic3x.c

        data = snd_soc_read(codec, AIC3X_PLL_PROGA_REG);
        snd_soc_write(codec, AIC3X_PLL_PROGA_REG,
                      data | (pll_p << PLLP_SHIFT));

In the above code, pll-p value is OR'ed with previous value without
clearing it. Bug is not seen if pll-p value doesn't change across
Sampling frequency.

However on some platforms (like AM335x EVM-SK), pll-p may have different
values across different sampling frequencies. In such case, above code
configures the pll with a wrong value.
Because of this bug, when a audio stream is played with pll value
different from previous stream, audio is heard as differently(like its
stretched).

Signed-off-by: Hebbar, Gururaja <gururaja.hebbar@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org