doc: update optional arguments for passthrough devices

This patch adds the description of newly added optional parameters for
PCI device passthrough. The new parameters are related to irq and
acpi dsdt info, which are designed for the passthrough of LPSS devices.

Tracked-On: #8615

Signed-off-by: Na Cui <na.cui@intel.com>

doc/user-guides/acrn-dm-parameters.rst

@@ -542,6 +542,10 @@ arguments:
          capability.  The specific virtual bar will be allocated.
        * ``enable_ptm``: enable PCIe precise time measurement mechanism for the
          passthrough device.
+       * ``irq=<irq_number>``: when the passthrough PCI devices support legacy interrupt,
+         e.g. UART, SDIO controller, ``irq_number`` shall be specified.
+       * ``dsdt=<dsdt_file_dir>``: when the passthrough PCI devices support legacy interrupt
+         and customized ``dsdt_file`` are needed , e.g. SPI, ``dsdt_file_dir`` shall be specified.
 
    * - ``uart``
      - Emulated PCI UART. Use the parameter with the format