omap mailbox: print hardware revision at startup

Signed-off-by: NHiroshi DOYU <Hiroshi.DOYU@nokia.com>

arch/arm/mach-omap2/mailbox.c

@@ -74,6 +74,9 @@ static int omap2_mbox_startup(struct omap_mbox *mbox)
 	}
 	clk_enable(mbox_ick_handle);
 
+	l = mbox_read_reg(MAILBOX_REVISION);
+	pr_info("omap mailbox rev %d.%d\n", (l & 0xf0) >> 4, (l & 0x0f));
+
 	/* set smart-idle & autoidle */
 	l = mbox_read_reg(MAILBOX_SYSCONFIG);
 	l |= 0x00000011;