clk: qcom: clk-alpha-pll: Add the list_registers callback for Trion PLLs

Add the list_registers callback for Trion PLLs in order to allow
printing their register states for debugging information.

Change-Id: I9965f44572068f424b87d6e5d51a9a33c1b8495f
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>