AT91: Use AT91_CPU_CLOCK in displays

Introduce AT91_CPU_CLOCK and use it for displaying the CPU
speed in the LCD driver.

Also make AT91_MAIN_CLOCK and AT91_MASTER_CLOCK reflect the
corresponding board clocks.

Signed-off-by: Stelian Pop <stelian@popies.net>
diff --git a/include/configs/at91sam9rlek.h b/include/configs/at91sam9rlek.h
index 648d60e..35dac47 100644
--- a/include/configs/at91sam9rlek.h
+++ b/include/configs/at91sam9rlek.h
@@ -29,9 +29,10 @@
 
 /* ARM asynchronous clock */
 #define AT91_CPU_NAME		"AT91SAM9RL"
-#define AT91_MAIN_CLOCK		200000000	/* from 12.000 MHz crystal */
-#define AT91_MASTER_CLOCK	100000000	/* peripheral = main / 2 */
-#define CONFIG_SYS_HZ			1000000		/* 1us resolution */
+#define AT91_MAIN_CLOCK		12000000	/* 12 MHz crystal */
+#define AT91_MASTER_CLOCK	100000000	/* peripheral */
+#define AT91_CPU_CLOCK		200000000	/* cpu */
+#define CONFIG_SYS_HZ		1000000		/* 1us resolution */
 
 #define AT91_SLOW_CLOCK		32768	/* slow clock */