ASoC: wm8940: Fix mask for setting BCLKDIV

According to the datasheet:
BCLK is controlled by BIT[4:2] of WM8940_CLOCK(06h) register.
Signed-off-by: Chris Paulson-Ellis <chris@edesix.com>
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/codecs/wm8940.c

@@ -621,7 +621,7 @@ static int wm8940_set_dai_clkdiv(struct snd_soc_dai *codec_dai,
 
 	switch (div_id) {
 	case WM8940_BCLKDIV:
-		reg = snd_soc_read(codec, WM8940_CLOCK) & 0xFFEF3;
+		reg = snd_soc_read(codec, WM8940_CLOCK) & 0xFFE3;
 		ret = snd_soc_write(codec, WM8940_CLOCK, reg | (div << 2));
 		break;
 	case WM8940_MCLKDIV: