omap-common: Common serial and usbethaddr functions based on die id

Now that we have a common prototype to grab the omap die id, functions to figure
out a serial number and usb ethernet address can use it directly.
Those also get an omap_die_id prefix for better consistency.

Signed-off-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/board/ti/omap5_uevm/evm.c b/board/ti/omap5_uevm/evm.c
index 0484087..853f196 100644
--- a/board/ti/omap5_uevm/evm.c
+++ b/board/ti/omap5_uevm/evm.c
@@ -189,14 +189,11 @@
  */
 int misc_init_r(void)
 {
-	unsigned int die_id[4] = { 0 };
-
 #ifdef CONFIG_PALMAS_POWER
 	palmas_init_settings();
 #endif
 
-	omap_die_id(die_id);
-	usb_fake_mac_from_die_id(die_id);
+	omap_die_id_usbethaddr();
 
 	return 0;
 }