ASoC: mxs-sgtl5000: Remove MCLK restriction

According to the sgtl5000 datasheet the MCLK frequency range restriction of
8 to 27 MHz only applies when the PLL is used - synchronous SYS_MCLK input mode.

mxs-sgtl5000 machine sets the codec as slave, and mx28 generates MCLK in the
range of 256*fs, 384*fs or 512*fs, which is called asynchronous SYS_MCLK
input.

In asynchronous SYS_MCLK we cannot have the 8 to 27 MHz check because if we
want to play a 8KHz sample rate track, with a MCLK of 8k * 512 = 4.096MHz the
current check would return -EINVAL, which is not correct.

Remove the 8 to 27MHz frequency check, since this only applies to the
synchronous SYS_MCLK input case.
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

sound/soc/mxs/mxs-sgtl5000.c

@@ -49,13 +49,6 @@ static int mxs_sgtl5000_hw_params(struct snd_pcm_substream *substream,
 		break;
 	}
 
-	/* Sgtl5000 sysclk should be >= 8MHz and <= 27M */
-	if (mclk < 8000000 || mclk > 27000000) {
-		dev_err(codec_dai->dev, "Invalid mclk frequency: %u.%03uMHz\n",
-			mclk / 1000000, mclk / 1000 % 1000);
-		return -EINVAL;
-	}
-
 	/* Set SGTL5000's SYSCLK (provided by SAIF MCLK) */
 	ret = snd_soc_dai_set_sysclk(codec_dai, SGTL5000_SYSCLK, mclk, 0);
 	if (ret) {