clk: qcom: clk-rcg: update DEFINE_RCG_DFS() macro

Update the DEFINE_RCG_DFS() macro to avoid the potential clock
struct name aliasing.

This modification originally came from:
commit c88b8062898c ("clk: qcom: Add cdiv clocks for gcc, video
and camera cc driver for KONA").

Change-Id: I5a8b694b5b8a8b5169639a3e09b1ab4c1936e010
Signed-off-by: David Collins <collinsd@codeaurora.org>