phy: qcom: qmp-pcie: restore compatibility with existing DTs

Existing device trees specify only a single clock-output-name for the
PCIe PHYs. The function phy_aux_clk_register() expects a second entry in
that property. When it doesn't find it, it returns an error, thus
failing the probe of the PHY and thus breaking support for the
corresponding PCIe host.

Follow the approach of the combo USB+DT PHY and generate the name for
the AUX clocks instead of requiring it in DT.

Fixes: 583ca9cc

 ("phy: qcom: qmp-pcie: register second optional PHY AUX clock")
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20240614-fix-pcie-phy-compat-v3-1-730d1811acf4@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>