soc:msm: Update routing of MSM_FRONTEND_DAI_MULTIMEDIA1

[0: AudioIn_8: 2615] MSM8960 Media1: asoc: MSM8960 Media1 no valid capture route from source to sink
ERROR: [0: AudioIn_8: 2615] MSM8960 Media1: dsp: no backend DAIs enabled for MSM8960 Media1

* In our snd_soc_msm_2x we have MultiMedia1 Mixer routed to AUX_PCM_TX sink.
* Currently the frontend doesnt have support for this in mixer_controls but does allow it(line 1539).

This allows for the DAI Backend to be enabled for MSM8960 Media1.