ASoC: imx-rpmsg: Add headphone jack detection and driver_name support

Chancel Liu <chancel.liu@nxp.com> says:

This series adds two features to the i.MX RPMSG ASoC card:
1. Headphone jack detection via GPIO: Introduce the "hp-det-gpios"
   device tree property and use simple_util_init_jack() to
   register a headphone jack with GPIO-based insertion detection.

2. driver_name assignment: Set driver_name on the snd_soc_card to
   "imx-audio-rpmsg", enabling userspace tools such as UCM to reliably
   identify the card by driver name regardless of the board-specific
   card name.

Link: https://patch.msgid.link/20260528020725.2265321-1-chancel.liu@nxp.com