PCI: tegra194: Fix duplicate PLL disable in pex_ep_event_pex_rst_assert()

PCI: tegra194: Fix duplicate PLL disable in pex_ep_event_pex_rst_assert()

During PERST# assertion tegra_pcie_bpmp_set_pll_state() is currently
called twice.

pex_ep_event_pex_rst_assert() should do the opposite of
pex_ep_event_pex_rst_deassert(), so it is obvious that the duplicate
tegra_pcie_bpmp_set_pll_state() is a mistake, and that the duplicate
tegra_pcie_bpmp_set_pll_state() call should instead be a call to
tegra_pcie_bpmp_set_ctrl_state().

With this, the uninitialization sequence also matches that of
tegra_pcie_unconfig_controller().

Fixes: a54e19073718 ("PCI: tegra194: Add Tegra234 PCIe support")
Signed-off-by: Nagarjuna Kristam <nkristam@nvidia.com>
[cassel: improve commit log]
Signed-off-by: Niklas Cassel <cassel@kernel.org>
Link: https://patch.msgid.link/20250911093021.1454385-2-cassel@kernel.org
[mani: added Fixes tag]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>