ASoC: ti: omap-hdmi: Fix too long driver name

Set driver name to "HDMI". This simplifies the code and gets rid of
the following error messages:

  ASoC: driver name too long 'HDMI 58040000.encoder' -> 'HDMI_58040000_e'

Signed-off-by: Primoz Fiser <primoz.fiser@norik.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com>
Link: https://lore.kernel.org/r/20240610125847.773394-1-primoz.fiser@norik.com
Signed-off-by: Mark Brown <broonie@kernel.org>