hactive, hfp, hbp, hsync needs to be halved for dual link MIPI Panels.
Accordingly timing related mmio regs needs to be programmed for both MIPI Ports.

v2: Address review comments by Jani
    - Used a for loop instead of do-while loop

v3: Used for_each_dsi_port macro instead of for loop
Signed-off-by: Gaurav K Singh <gaurav.k.singh@intel.com>
Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>