ASoC: meson: g12a-tohdmitx: require regmap mmio

The tohdmitx glue uses regmap MMIO so it should require it.

Fixes: c8609f38 ("ASoC: meson: add g12a tohdmitx control")
Signed-off-by: NJerome Brunet <jbrunet@baylibre.com>
Link: https://lore.kernel.org/r/20190820123510.22491-1-jbrunet@baylibre.comSigned-off-by: NMark Brown <broonie@kernel.org>

sound/soc/meson/Kconfig

@@ -87,6 +87,7 @@ config SND_MESON_AXG_PDM
 
 config SND_MESON_G12A_TOHDMITX
 	tristate "Amlogic G12A To HDMI TX Control Support"
+	select REGMAP_MMIO
 	imply SND_SOC_HDMI_CODEC
 	help
 	  Select Y or M to add support for HDMI audio on the g12a SoC