ASoC: dt-bindings: rt5659: Update binding doc

Update following in rt5659.txt binding doc
  - Add JD source for Intel HDA header: Commit 041e74b7
    ("ASoC: rt5659: Add the support of Intel HDA Header")
    added driver support. Add missing info here.

  - sound-name-prefix: Used to prefix component widgets/kcontrols
    with given prefix.

  - ports: Helps to use the Codec with audio graph card

Signed-off-by: Sameer Pujar <spujar@nvidia.com>
Reported-by: Jon Hunter <jonathanh@nvidia.com>
Cc: Oder Chiou <oder_chiou@realtek.com>
Cc: Bard Liao <bardliao@realtek.com>
Link: https://lore.kernel.org/r/1611944866-29373-2-git-send-email-spujar@nvidia.com


Signed-off-by: Mark Brown <broonie@kernel.org>