rpi: fix up Model B entries

The P5 header was not present on "Model B" any board prior to Revision 2.0,
there's no need for a separate device tree.

Also, it looks like "rev2" is incorrectly used to only cover the 512MiB
memory models; there also were 256MiB 2.0 boards.

I don't have all of the boards to check this, I'm following this table:
http://elinux.org/RPi_HardwareHistory#Board_Revision_History

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>

board/raspberrypi/rpi/rpi.c

@@ -115,28 +115,28 @@ static const struct rpi_model rpi_models_new_scheme[] = {
 
 static const struct rpi_model rpi_models_old_scheme[] = {
 	[0x2] = {
-		"Model B (no P5)",
-		"bcm2835-rpi-b-i2c0.dtb",
+		"Model B",
+		"bcm2835-rpi-b.dtb",
 		true,
 	},
 	[0x3] = {
-		"Model B (no P5)",
-		"bcm2835-rpi-b-i2c0.dtb",
+		"Model B",
+		"bcm2835-rpi-b.dtb",
 		true,
 	},
 	[0x4] = {
-		"Model B",
-		"bcm2835-rpi-b.dtb",
+		"Model B rev2",
+		"bcm2835-rpi-b-rev2.dtb",
 		true,
 	},
 	[0x5] = {
-		"Model B",
-		"bcm2835-rpi-b.dtb",
+		"Model B rev2",
+		"bcm2835-rpi-b-rev2.dtb",
 		true,
 	},
 	[0x6] = {
-		"Model B",
-		"bcm2835-rpi-b.dtb",
+		"Model B rev2",
+		"bcm2835-rpi-b-rev2.dtb",
 		true,
 	},
 	[0x7] = {