forked from Mirrors/opensbi

We add fdt_parse_timebase_frequency() function which can be used by ACLINT mtimer driver and platform code to get timebase frequency. Signed-off-by: Anup Patel <anup.patel@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Xiang W <wxjstz@126.com>