linuxkpi: Add media-bus-format.h

Provide macros needed for drm-kmod.

Obtain from: OpenBSD (via drm-kmod)
MFC after: 1 week
Sponsored by: Beckhoff Automation GmbH & Co. KG
Differential Revision: https://reviews.freebsd.org/D35565

(cherry picked from commit 7e4f9ebeaab420b16a8041194c687e624be5b3f9)