cec: add cec_s_phys_addr_from_edid helper function

This function simplifies the integration of CEC in DRM drivers.

Change-Id: I5c3798fdd6594c22071df1103b487c80e01f128d
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Git-commit: 23111ec304166750479e17318b7175ff7db0d6ac
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


[vvalluru@codeaurora.org: resolved merge conflicts]
Signed-off-by: Venkata Prahlad Valluru <vvalluru@codeaurora.org>