Beaglebone Black HDMI support v2

[Oleksandr Tymoshenko]

Hello,

Here is the second version of the patch:
https://people.freebsd.org/~gonzo/arm/patches/bbb-hdmi-20150128.diff

Changes comparing to previous version:

- Config switched to vt(4)
- EDID parser from NetBSD
- Driver picks up the best matching videomode
- “naive” implementation of hdmi_if: HDMI connect events, read EDID, and  set framer videomode. 

You need HEAD with r277871 for this patch to work reliably

-- 
gonzo