rc: add BB-BONELT-HDMIN virtual cape

On the BealgeBone Black, the on-board HDMI acts like a "virtual"
cape; it uses pins on the expansion header and can conflict with
other capes.

This commit moves the tda19988 service start-up from rc to it's
own script so that it can be easily disabled automatically when
an LCD cape is present and enabled the rest of the time.

Change-Id: I564463dd2fc34eab44dfe65a61038d5c89407730
fb: port to am335x (work-in-progress)

Change-Id: I0dbc345c3bf7500b181f02f06376d2d09c860585
splash: framebuffer test program

Change-Id: I7e045a4c6cec476615057f46f530693c0a2a17e0
splash: use parameters provided by the fb driver

Certain parameters, such as screen resolution, differ between
monitors. Enhance the splash program to dynamically configure
itself.

Change-Id: I49b0a3704decb7cb4633a1ee424b0419a1d67cf0