omap mailbox: print hardware revision at startup

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

diff --git a/arch/arm/mach-omap2/mailbox.c b/arch/arm/mach-omap2/mailbox.c
index d925ef3..44e9101 100644
--- a/arch/arm/mach-omap2/mailbox.c
+++ b/arch/arm/mach-omap2/mailbox.c
@@ -74,6 +74,9 @@
 	}
 	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;