vga: add Matrox G550
 [rsc] --rw-rw-r-- M 177229 glenda sys 29342 Apr  1 16:40 lib/vgadb
	/n/sourcesdump/2006/0401/plan9/lib/vgadb:380,388 - 
	/n/sourcesdump/2006/0402/plan9/lib/vgadb:380,388
	  	hwgc=vmwarehwgc
	  
	  ctlr
	- 	0xC002D="MATROX/Matrox G400"
	- 	0xC002D="MATROX/Matrox G450"
	- 	0xC002D="MATROX/MGA-G200 VGA"
	+ 	vid=0x102B did=0x0521		# Matrox G200
	+ 	vid=0x102B did=0x0525		# Matrox G450
	+ 	vid=0x102B did=0x2527		# Matrox G550
	  	link=vga
	  	ctlr=mga4xx linear=1
	  	hwgc=mga4xxhwgc
 [rsc] --rw-rw-r-- M 177229 glenda sys 9573 Apr  1 16:44 sys/src/9/pc/vgamga4xx.c
	/n/sourcesdump/2006/0401/plan9/sys/src/9/pc/vgamga4xx.c:20,25 - 
	/n/sourcesdump/2006/0402/plan9/sys/src/9/pc/vgamga4xx.c:20,26
	  
	  enum {
	  	MATROX			= 0x102B,
	+ 	MGA550			= 0x2527,
	  	MGA4xx			= 0x0525,
	  	MGA200			= 0x0521,
	  
	/n/sourcesdump/2006/0401/plan9/sys/src/9/pc/vgamga4xx.c:78,83 - 
	/n/sourcesdump/2006/0402/plan9/sys/src/9/pc/vgamga4xx.c:79,86
	  	
	  	p = pcimatch(nil, MATROX, MGA4xx);
	  	if(p == nil)
	+ 		p = pcimatch(nil, MATROX, MGA550);
	+ 	if(p == nil)
	  		p = pcimatch(nil, MATROX, MGA200);
	  	return p;
	  }
	/n/sourcesdump/2006/0401/plan9/sys/src/9/pc/vgamga4xx.c:132,138 - 
	/n/sourcesdump/2006/0402/plan9/sys/src/9/pc/vgamga4xx.c:135,141
	  	addvgaseg("mga4xxmmio", pci->mem[1].bar&~0x0F, pci->mem[1].size);
	  
	  	/* need to map frame buffer here too, so vga can find memory size */
	- 	if(pci->did == MGA4xx)
	+ 	if(pci->did == MGA4xx || pci->did == MGA550)
	  		size = 32*MB;
	  	else
	  		size = 8*MB;
	/n/sourcesdump/2006/0401/plan9/sys/src/9/pc/vgamga4xx.c:464,472 - 
	/n/sourcesdump/2006/0402/plan9/sys/src/9/pc/vgamga4xx.c:467,475
	  	uchar *mga;
	   	Pcidev *p;
	  
	- 	p = pcimatch(nil, MATROX, MGA4xx);
	- 	if(p == nil)
	- 		return ;
	+ 	p = mgapcimatch();
	+ 	if(p->did == MGA200)
	+ 		return;
	  
	  	if(scr->mmio == 0)
	  		return;
 [rsc] --rw-rw-r-- M 177229 glenda sys 36098 Apr  1 16:44 sys/src/cmd/aux/vga/mga4xx.c
	[diffs elided - too long]
	[diff -c /n/sourcesdump/2006/0401/plan9/sys/src/cmd/aux/vga/mga4xx.c /n/sourcesdump/2006/0402/plan9/sys/src/cmd/aux/vga/mga4xx.c]