omap-common: Common omap_die_id definition

This introduces a common definition for omap_die_id, that aims at providing a
common interface for accessing omap platform's die id bits.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/cpu/armv7/omap-common/utils.c b/arch/arm/cpu/armv7/omap-common/utils.c
index df5f817..acff16b 100644
--- a/arch/arm/cpu/armv7/omap-common/utils.c
+++ b/arch/arm/cpu/armv7/omap-common/utils.c
@@ -41,6 +41,11 @@
 	}
 }
 
+__weak void omap_die_id(unsigned int *die_id)
+{
+	die_id[0] = die_id[1] = die_id[2] = die_id[3] = 0;
+}
+
 void __weak usb_fake_mac_from_die_id(u32 *id)
 {
 	uint8_t device_mac[6];
diff --git a/arch/arm/include/asm/omap_common.h b/arch/arm/include/asm/omap_common.h
index 81f1616..6e0b8d7 100644
--- a/arch/arm/include/asm/omap_common.h
+++ b/arch/arm/include/asm/omap_common.h
@@ -612,6 +612,8 @@
 void enable_edma3_clocks(void);
 void disable_edma3_clocks(void);
 
+void omap_die_id(unsigned int *die_id);
+
 /* ABB */
 #define OMAP_ABB_NOMINAL_OPP		0
 #define OMAP_ABB_FAST_OPP		1