configs: stm32f4xx: Remove CONFIG_SYS_RAM_FREQ_DIV

Since commit bfea69ad ("stm32f7: sdram: correct sdram
configuration as per micron sdram"), CONFIG_SYS_RAM_FREQ_DIV
flag is no more used, remove it.
Signed-off-by: NPatrice Chotard <patrice.chotard@st.com>

include/configs/stm32f429-discovery.h

@@ -17,7 +17,6 @@
  * Configuration of the external SDRAM memory
  */
 #define CONFIG_NR_DRAM_BANKS		1
-#define CONFIG_SYS_RAM_FREQ_DIV		2
 #define CONFIG_SYS_LOAD_ADDR		0x90400000
 #define CONFIG_LOADADDR			0x90400000
 

include/configs/stm32f429-evaluation.h

@@ -17,7 +17,6 @@
  * Configuration of the external SDRAM memory
  */
 #define CONFIG_NR_DRAM_BANKS		1
-#define CONFIG_SYS_RAM_FREQ_DIV		2
 #define CONFIG_SYS_LOAD_ADDR		0x00400000
 #define CONFIG_LOADADDR			0x00400000
 

include/configs/stm32f469-discovery.h

@@ -17,7 +17,6 @@
  * Configuration of the external SDRAM memory
  */
 #define CONFIG_NR_DRAM_BANKS		1
-#define CONFIG_SYS_RAM_FREQ_DIV		2
 #define CONFIG_SYS_LOAD_ADDR		0x00400000
 #define CONFIG_LOADADDR			0x00400000