arm: omap: add support for am57xx devices

just add a few ifdefs around because this
device is very similar to dra7xxx.

Signed-off-by: Felipe Balbi <balbi@ti.com>
Reviewed-by: Tom Rini <trini@ti.com>
diff --git a/arch/arm/include/asm/arch-omap5/clock.h b/arch/arm/include/asm/arch-omap5/clock.h
index 7eacba2..0dc584b 100644
--- a/arch/arm/include/asm/arch-omap5/clock.h
+++ b/arch/arm/include/asm/arch-omap5/clock.h
@@ -314,7 +314,7 @@
  */
 #define CONFIG_DEFAULT_OMAP_RESET_TIME_MAX_USEC	31219
 
-#ifdef CONFIG_DRA7XX
+#if defined(CONFIG_DRA7XX) || defined(CONFIG_AM57XX)
 #define V_OSCK			20000000	/* Clock output from T2 */
 #else
 #define V_OSCK			19200000	/* Clock output from T2 */