ASoC: codec: tlv320aic32x4: Fix regmap range config

This codec driver fails to probe because it has a higher regmap
range_max value than max_register. This patch sets the range_max to the
max_register value as described in the for struct regmap_range_cfg:
"@range_max: Address of the highest register in virtual range."

Fixes: 4d208ca4 (ASoC: tlv320aic32x4: Convert to direct regmap API usage)
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org (v3.13 if the fix misses -final)