ARM: bcm283x: Include definition for additional emmc clock

This clock has a different mbox ID so have this included in the relevant
header file.

Signed-off-by: Andrei Gherzan <andrei@balena.io>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
diff --git a/arch/arm/mach-bcm283x/include/mach/mbox.h b/arch/arm/mach-bcm283x/include/mach/mbox.h
index 1e4718d..0b6c254 100644
--- a/arch/arm/mach-bcm283x/include/mach/mbox.h
+++ b/arch/arm/mach-bcm283x/include/mach/mbox.h
@@ -233,6 +233,7 @@
 #define BCM2835_MBOX_CLOCK_ID_SDRAM	8
 #define BCM2835_MBOX_CLOCK_ID_PIXEL	9
 #define BCM2835_MBOX_CLOCK_ID_PWM	10
+#define BCM2835_MBOX_CLOCK_ID_EMMC2	12
 
 struct bcm2835_mbox_tag_get_clock_rate {
 	struct bcm2835_mbox_tag_hdr tag_hdr;