Revert "[media] s5p-mfc: Fix frame skip bug"

This reverts commit 90c0ae50097bba165022ddf0a592aa4001e23aaa.
As explained by Sjoerd:

This commit changes where it looks for that information on all versions
of the MFC, which clearly did not have the intended result on the MFC
version on the odroid, while it works fine on the chromebooks.

So either between mfc v5 and newer ones you need to read a different
register to get the same information or reading the one in the patch
is correct but the values are different

For other hardware specific things the per-version specific code
translate status fields from the hw specific variation to a "common"
value, but it doesn't do so for this specific one.