PCI: dwc: Record integrated eDMA register window

PCI: dwc: Record integrated eDMA register window

Some DesignWare PCIe controllers integrate an eDMA block whose registers
are located in a dedicated register window.

The EP-side aux-resource code exposes an interrupt-emulation doorbell
register (DOORBELL_MMIO) from that window. Its location is derived from
the start of the eDMA register window plus the doorbell offset already
provided by dw-edma, and the window size is used to validate the
computed register location.

Record the physical base and size of the integrated eDMA register window
in struct dw_pcie so the EP-side DesignWare aux-resource provider can
construct that doorbell resource.

Signed-off-by: Koichiro Den <den@valinux.co.jp>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Tested-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://patch.msgid.link/20260414141514.1341429-3-den@valinux.co.jp