ASoC: BCM:Add support for HiFiBerry Digi. Driver is based on the patched WM8804 driver.

Signed-off-by: Daniel Matuschek <daniel@matuschek.net>

Add a parameter to turn off SPDIF output if no audio is playing

This patch adds the paramater auto_shutdown_output to the kernel module.
Default behaviour of the module is the same, but when auto_shutdown_output
is set to 1, the SPDIF oputput will shutdown if no stream is playing.

bugfix for 32kHz sample rate, was missing

HiFiBerry Digi: set SPDIF status bits for sample rate

The HiFiBerry Digi driver did not signal the sample rate in the SPDIF status bits.
While this is optional, some DACs and receivers do not accept this signal. This patch
adds the sample rate bits in the SPDIF status block.

Added HiFiBerry Digi+ Pro driver

Signed-off-by: Daniel Matuschek <daniel@hifiberry.com>