ARM: rpi: add another revision of Raspberry Pi A+

Seen this one in the wild. Is labelled "Raspberry Pi Model A+ V1.1,
(C) Raspberry Pi 2014". A standard A+ board, much like the one with
version 0x12, didn't notice any differencies.

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

arch/arm/mach-bcm283x/include/mach/mbox.h

@@ -150,6 +150,7 @@ struct bcm2835_mbox_tag_hdr {
 #define BCM2835_BOARD_REV_A_PLUS	0x12
 #define BCM2835_BOARD_REV_B_PLUS_13	0x13
 #define BCM2835_BOARD_REV_CM_14		0x14
+#define BCM2835_BOARD_REV_A_PLUS_15	0x15
 #endif
 
 struct bcm2835_mbox_tag_get_board_rev {

board/raspberrypi/rpi/rpi.c

@@ -176,6 +176,11 @@ static const struct {
 		"bcm2835-rpi-cm.dtb",
 		false,
 	},
+	[BCM2835_BOARD_REV_A_PLUS_15] = {
+		"Model A+",
+		"bcm2835-rpi-a-plus.dtb",
+		false,
+	},
 #endif
 };