clk: qcom: gcc-kona: make pcie_refgen_clk_src supressible

Move the gcc_pcie_refgen_clk_src voltage domain and parents
to active_only. This will make requirements of this clock effectively
supressible even if consumers left this clock always on. The purpose
of this change is to faciliate the handoff of this clock to LPASS
by having the HLOS make its vote supressible. This approach
trusts that the requirement of this clock is met elsewhere through
PCIE consumers in the event that the HLOS goes to sleep.

Change-Id: I5e08586c9d99ad41d86903a44326b00c9001ba1f
Signed-off-by: David Dai <daidavid1@codeaurora.org>