clk: versal: Fix the function versal_clock_ref

For reference clocks, PM_CLK_GET_PARENT call is not allowed.
PM_CLK_GET_PARENT only allowed for MUX clocks. Rename the
versal_clock_ref() with versal_clock_get_ref_rate() for better
readability. Fix the versal_clock_get_ref_rate function by
passing the parent_id, and check whether the parent_id
belongs to ref_clk or pl_alt_ref_clk.
Also adding the function versal_clock_get_fixed_factor_rate()
if the clk_id belongs to the fixed factor clock.

Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
Link: https://lore.kernel.org/r/20230912033055.2549-1-venkatesh.abbarapu@amd.com


Signed-off-by: Michal Simek <michal.simek@amd.com>