arm: lager: Disable TMU0 before OS boot

On U-boot uses TMU0 as timer, but TMU0 does not use on linux kernel
and other.
This disables TMU0 at the request of from kernel user.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>

board/renesas/lager/lager.c

@@ -254,6 +254,12 @@ int board_early_init_f(void)
 	return 0;
 }
 
+void arch_preboot_os(void)
+{
+	/* Disable TMU0 */
+	mstp_setbits_le32(MSTPSR1, SMSTPCR1, TMU0_MSTP125);
+}
+
 DECLARE_GLOBAL_DATA_PTR;
 int board_init(void)
 {