Enhancements to pcie-tegra194 driver

This series[1] was originally posted by Vidya Sagar, and I have rebased
it onto 6.19.0-rc6-next. I addressed review comments, reworked a patch
and included four new patches. I verified these patches on Jetson AGX
Orin(Tegra234 SoC).

Disabling L1SS capability based on support-clkreq device tree property
is moved to common DWC driver, so I reworked below patch to disable
just L1.2 capability on Tegra234 SoC.
 - PCI: tegra194: Disable L1.2 capability of Tegra234 EP

I added below four new patches to fix bugs, commit message of each
patch has the details on the bug and fix.
 - PCI: tegra194: Add ASPM L1 entrance latency config
 - PCI: tegra194: Use HW version number
 - PCI: tegra194: Fix CBB timeout caused by DBI access before core power-on
 - PCI: tegra194: Disable PERST IRQ only in Endpoint mode 

I added more context in the commit message for below patch based on review
comment in V3.
 - PCI: tegra194: Remove IRQF_ONESHOT flag during Endpoint interrupt registration

Rest of the patches are same as the original V3 series, just rebased them on
6.19.0-rc6-next.

Verification details.
 - I verified both Root port and Endpoint mode controllers on Tegra234 SoC.
 - Basic sanity Link up, configuration space access and BAR access are verified.
 - I verified that ASPM L1.2 capability is disabled for Endpoint mode.
 - I verified suspend to RAM tests with Endpoint mode.

[1] https://patchwork.kernel.org/project/linux-pci/patch/2022...

Manikanta Maddireddy (4):
  PCI: tegra194: Add ASPM L1 entrance latency config
  PCI: tegra194: Use HW version number
  PCI: tegra194: Fix CBB timeout caused by DBI access before core
    power-on
  PCI: tegra194: Disable PERST IRQ only in Endpoint mode

Vidya Sagar (18):
  PCI: tegra194: Use devm_gpiod_get_optional() to parse
    "nvidia,refclk-select"
  PCI: tegra194: Drive CLKREQ signal low explicitly
  PCI: tegra194: Fix polling delay for L2 state
  PCI: tegra194: Apply pinctrl settings for both PCIe RP and EP
  PCI: tegra194: Refactor LTSSM state polling on surprise down
  PCI: tegra194: Disable direct speed change for EP
  PCI: tegra194: Calibrate P2U for endpoint mode
  PCI: tegra194: Free resources during controller deinitialization
  PCI: tegra194: Remove IRQF_ONESHOT flag during Endpoint interrupt
    registration
  PCI: tegra194: Enable DMA interrupt
  PCI: tegra194: Enable hardware hot reset mode in Endpoint
  PCI: tegra194: Allow system suspend when the Endpoint link is not up
  PCI: tegra194: Disable L1.2 capability of Tegra234 EP
  PCI: tegra194: Set LTR message request before PCIe link up
  PCI: tegra194: Don't force the device into the D0 state before L2
  PCI: tegra194: Free up EP resources during remove()
  dt-bindings: PCI: tegra194: Add monitor clock support
  PCI: tegra194: Add core monitor clock support

 .../bindings/pci/nvidia,tegra194-pcie-ep.yaml |   6 +-
 .../bindings/pci/nvidia,tegra194-pcie.yaml    |   6 +-
 drivers/pci/controller/dwc/pcie-designware.c  |   2 +-
 drivers/pci/controller/dwc/pcie-designware.h  |   2 +
 drivers/pci/controller/dwc/pcie-tegra194.c    | 268 +++++++++++-------
 5 files changed, 181 insertions(+), 103 deletions(-)

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2.34.1