radeonfb: Add ATOM BIOS parsing (rebased patch)

Signed-Off-By:  Solomon Peachy <redacted>

This is my old radeon-atom-5 patch rediffed against 2.6.17.x

Changes vs 2.6.17.x:

 * ATOM BIOS support for newer Radeon cards
 * Clean method of detecting and handling disparate BIOS types
 * Radeon RV410/M26/M26GL (aka Mobility X700/FireGL5000) card IDs
 * Default PLL clocks for R420 and variants
 * Handle bogus PLL divider with sane default.
 * All new connector/head detection code that uses bios/firmware
   defaults whenever possible.

...

A while back I posted a patch that added full ATOM BIOS parsing for
newer radeon boards.  It also re-jiggered multi head detection to be
considerably more sane (== actually work), and generally modularized
most of the "get data X from BIOS/firmware/etc" code. 

I was working under BenH's direction, but he apparently got swamped a
while back and this fell through the cracks.  I'm re-posting this in an
attempt to get the ball rolling again, as several people have contacted 
me directly to ask about this code getting merged.

I don't have the means (hardware &| bug reports/feedback) to develop it
further.  IIRC the memmap fixes for r300/r400 haven't been integrated
into the mainline either, so you may get some random lockups -- but that
is beyond the scope of this patch.

Aanyone who has a radeon card and is feeling brave, please give this a
whirl.  If you are specifying a monitor layout, try it without the
layout string and things should JustWork(tm).

This patch also adds PCI IDs for the X700/M26 series.  It tests fine on 
the M26 (ATOM) in my laptop and the 7500AGP (Legacy) card in my workstation.

See also kernel bugzilla # 6215:

	http://bugzilla.kernel.org/show_bug.cgi?id=6215

I'll rebase it against 2.6.18-rcX (if necessary) after I migrate to 
2.6.18-rcX on my development boxen.

 - Solomon
-- 
Solomon Peachy        		       pizza at shaftnet dot org	 
Melbourne, FL                          ^^ (mail/jabber/gtalk) ^^
Quidquid latine dictum sit, altum viditur.          ICQ: 1318344