clk: rockchip: add dt-binding header for rk1808

Add the dt-bindings header for the rk1808, that gets shared between
the clock controller and the clock references in the dts.
Add softreset ID for rk1808.

Change-Id: I0eef08655037daeab92560f36e06fde4032ddd0c
Signed-off-by: Elaine Zhang <[email protected]>

Author: Elaine Zhang