at91: Defined main clock frequency on esd at91 boards

Autodetection is undesired now

Signed-off-by: Daniel Gorsulowski <Daniel.Gorsulowski@esd.eu>
Signed-off-by: Reinhard Meyer <u-boot@emk-elektronik.de>
diff --git a/include/configs/otc570.h b/include/configs/otc570.h
index fb0f576..4a1cede 100644
--- a/include/configs/otc570.h
+++ b/include/configs/otc570.h
@@ -35,6 +35,7 @@
 #define CONFIG_OTC570			1	/* Board is esd OTC570 */
 #define CONFIG_ARM926EJS		1	/* This is an ARM926EJS Core */
 #define CONFIG_AT91SAM9263		1	/* It's an AT91SAM9263 SoC */
+#define CONFIG_SYS_AT91_MAIN_CLOCK	16000000/* 16.0 MHz crystal */
 #define CONFIG_SYS_HZ			1000	/* decrementer freq */
 #define CONFIG_DISPLAY_BOARDINFO	1
 #define CONFIG_DISPLAY_CPUINFO		1	/* display cpu info and speed */