arm: rmobile: koelsch: Remove dram_init_banksize function

Koesch board is defined CONFIG_SYS_SDRAM_BASE, and this can use a basic function of
dram_init_banksize instead.
Signed-off-by: NNobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: NNobuhiro Iwamatsu <iwamatsu@nigauri.org>

board/renesas/koelsch/koelsch.c

@@ -90,7 +90,7 @@ void arch_preboot_os(void)
 int board_init(void)
 {
 	/* adress of boot parameters */
-	gd->bd->bi_boot_params = KOELSCH_SDRAM_BASE + 0x100;
+	gd->bd->bi_boot_params = CONFIG_SYS_SDRAM_BASE + 0x100;
 
 	/* Init PFC controller */
 	r8a7791_pinmux_init();
@@ -173,12 +173,6 @@ const struct rmobile_sysinfo sysinfo = {
 	CONFIG_RMOBILE_BOARD_STRING
 };
 
-void dram_init_banksize(void)
-{
-	gd->bd->bi_dram[0].start = KOELSCH_SDRAM_BASE;
-	gd->bd->bi_dram[0].size = KOELSCH_SDRAM_SIZE;
-}
-
 void reset_cpu(ulong addr)
 {
 	u8 val;