configs: stih410-b2260: Fix SYS_HZ_CLOCK value

SYS_HZ_CLOCK was wrongly set to 1GHz whereas it's set to 750MHz
by default by bootrom.

Signed-off-by: Patrice Chotard <patrice.chotard@foss.st.com>
Reviewed-by: Grzegorz Szymaszek <gszymaszek@short.pl>
diff --git a/include/configs/stih410-b2260.h b/include/configs/stih410-b2260.h
index b1a011b..1e966a2 100644
--- a/include/configs/stih410-b2260.h
+++ b/include/configs/stih410-b2260.h
@@ -14,7 +14,7 @@
 #define CONFIG_SYS_SDRAM_BASE		PHYS_SDRAM_1
 #define PHYS_SDRAM_1_SIZE		0x3E000000
 
-#define CONFIG_SYS_HZ_CLOCK		1000000000	/* 1 GHz */
+#define CONFIG_SYS_HZ_CLOCK		750000000	/* 750 MHz */
 
 /* Environment */