arm: rmobile: lager: Update calculation of CONFIG_SH_TMU_CLK_FREQ

CONFIG_SH_TMU_CLK_FREQ of lager is calculated from the external clock.
This defines RMOBILE_XTAL_CLK, this updates the calculation of
CONFIG_SH_TMU_CLK_FREQ.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/include/configs/lager.h b/include/configs/lager.h
index 5ddefef..269cfec 100644
--- a/include/configs/lager.h
+++ b/include/configs/lager.h
@@ -155,9 +155,10 @@
 #define CONFIG_SYS_I2C_POWERIC_ADDR 0x58 /* da9063 */
 
 /* Board Clock */
-#define CONFIG_BASE_CLK_FREQ	20000000u
-#define CONFIG_SH_TMU_CLK_FREQ	(CONFIG_BASE_CLK_FREQ / 2) /* EXT / 2 */
-#define CONFIG_PLL1_CLK_FREQ	(CONFIG_BASE_CLK_FREQ * 156 / 2)
+#define RMOBILE_XTAL_CLK	20000000u
+#define CONFIG_SYS_CLK_FREQ	RMOBILE_XTAL_CLK
+#define CONFIG_SH_TMU_CLK_FREQ	(CONFIG_SYS_CLK_FREQ / 2) /* EXT / 2 */
+#define CONFIG_PLL1_CLK_FREQ	(CONFIG_SYS_CLK_FREQ * 156 / 2)
 #define CONFIG_PLL1_DIV2_CLK_FREQ	(CONFIG_PLL1_CLK_FREQ / 2)
 #define CONFIG_MP_CLK_FREQ	(CONFIG_PLL1_DIV2_CLK_FREQ / 15)
 #define CONFIG_HP_CLK_FREQ	(CONFIG_PLL1_CLK_FREQ / 12)