DynamicTablesPkg: Fix Ssdt PCI generation comments

The second model of the _PRT object is used. Indeed:
- the interrupts described are not re-configurable
- OSes are aware of the polarity of PCI legacy interrupts,
  so there is no need to accurately describe the polarity.

Also, fix a comment for the CM_ARM_PCI_INTERRUPT_MAP_INFO obj.

Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

DynamicTablesPkg/Include/ArmNameSpaceObjects.h

@@ -1014,7 +1014,7 @@ typedef struct CmArmPciInterruptMapInfo {
   /// Value on 8 bits (max 255).
   UINT8    PciBus;
 
-  /// Pci Bus.
+  /// Pci Device.
   /// Value on 5 bits (max 31).
   UINT8    PciDevice;
 

DynamicTablesPkg/Library/Acpi/Arm/AcpiSsdtPcieLibArm/SsdtPcieGenerator.c

@@ -288,12 +288,6 @@ GeneratePciDeviceInfo (
 
   Cf. ACPI 6.4 specification, s6.2.13 "_PRT (PCI Routing Table)"
 
-  The first model (defining a _CRS object) is used. This is necessary because
-  PCI legacy interrupts are active low and GICv2 SPI interrupts are active
-  high.
-  Even though PCI interrupts cannot be re-routed, only the first model allows
-  to specify the activation state (low/high).
-
   @param [in]       Generator       The SSDT Pci generator.
   @param [in]       CfgMgrProtocol  Pointer to the Configuration Manager
                                     Protocol interface.
@@ -397,6 +391,8 @@ GeneratePrt (
        High word-Device #, Low word-Function #. (for example, device 3,
        function 2 is 0x00030002). To refer to all the functions on a device #,
        use a function number of FFFF).
+
+      Use the second model for _PRT object and describe a hardwired interrupt.
     */
     Status = AmlAddPrtEntry (
                (IrqMapInfo->PciDevice << 16) | 0xFFFF,