ASoC: meson: aiu: Validate written enum values

In the Linux kernel, the following vulnerability has been resolved: ASoC: meson: aiu: Validate written enum values The AIU HDMI and internal codec mux put callbacks use the written enum value with snd_soc_enum_item_to_val() before checking whether the value is valid for the enumeration. Reject out-of-range values before converting the enum item, matching the validation already done by the G12A HDMI and internal codec mux controls.