Only LS1046A and LS1028A require the base clk to be divided by 2. Implement that by moving the divider to a SoC specific data. This commit fixes base clk setup for the entire SoC family, including the already suported LS2160A. Submitted by: Lukasz Hajec <lha@semihalf.com> Reviewed by: manu Obtained from: Semihalf Sponsored by: Alstom Group Differential Revision: https://reviews.freebsd.org/D30120