ASoC: cygnus: Add Cygnus audio DAI driver

This patch adds Cygnus audio DAI driver. It supports I2S, TDM
and SPDIF modes and uses three clocks derived from PLL.

This patchset has been tested on Cygnus wireless audio
bcm958305K board.

Signed-off-by: Lori Hikichi <lhikichi@broadcom.com>
Signed-off-by: Simran Rai <ssimran@broadcom.com>
Reviewed-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Arun Parameswaran <arunp@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Mark Brown <broonie@kernel.org>