PCI: mediatek-gen3: Avoid PCIe resetting via PERST# for Airoha EN7581 SoC

JIRA: https://issues.redhat.com/browse/RHEL-83611
Upstream Status: 491cb9c5084790aafa02e843349492c284373231

commit 491cb9c5084790aafa02e843349492c284373231
Author: Lorenzo Bianconi <lorenzo@kernel.org>
Date:   Thu Jan 9 00:30:45 2025 +0100

    PCI: mediatek-gen3: Avoid PCIe resetting via PERST# for Airoha EN7581 SoC

    Airoha EN7581 has a hw bug asserting/releasing PERST# signal causing
    occasional PCIe link down issues. In order to overcome the problem,
    PERST# signal is not asserted/released during device probe or
    suspend/resume phase and the PCIe block is reset using
    en7523_reset_assert() and en7581_pci_enable().

    Introduce flags field in the mtk_gen3_pcie_pdata struct in order to
    specify per-SoC capabilities.

    Link: https://lore.kernel.org/r/20250109-pcie-en7581-rst-fix-v4-1-4a45c89fb143@kernel.org


Tested-by: Hui Ma <hui.ma@airoha.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>

Signed-off-by: Myron Stowe <mstowe@redhat.com>