ARM: dts: dra7xx-clocks: Change the parent of apll_pcie_in_clk_mux to dpll_pcie_ref_m2ldo_ck

Change the parent of apll_pcie_in_clk_mux to dpll_pcie_ref_m2ldo_ck
from dpll_pcie_ref_ck.

Figure 26-22. DPLL_PCIE_REF Functional Block Diagram in vE of DRA7xx ES1.0 TRM
shows the signal name for the output of post divider (M2) is CLKOUTLDO.

Figure 26-21. PCIe PHY Clock Generator Overview shows CLKOUTLDO is used as
input to apll mux.

So the actual output of dpll is dpll_pcie_ref_m2ldo_ck which is also the input
of apll.

Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>