ARM: dts: imx7-mba7: change sound card model name

ARM: dts: imx7-mba7: change sound card model name

The card name for ALSA is generated from the model name string and
is limited to 16 characters. Use a shorter name to prevent cutting the
name.

Since nearly all starter kit mainboards for i.MX based SoM by TQ-Systems
use the same codec with the same routing on board it is a good idea to
use the same mode name for the sound card. This allows sharing a default
asound.conf in BSP over all the kits.

Signed-off-by: Markus Niebel <Markus.Niebel@ew.tq-group.com>
Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>