Merge commit 'efc9194bcff84' ("ASoC: hdmi-codec: callback function will be called with private data") into drm-tda998x-devel

This commit is required for the TDA998x ASoC support, so to avoid build
errors, merge this commit into this branch prior to commiting Jiri's
patches.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>