SpcrFeaturePkg: Modify PCI device interrupt setting.

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3708



The original code will cause FWTS V21.08.00 testing failed.
 spcr: SPCR PC-AT compatible IRQ 0xff is invalid
 spcr: SPCR PCI flags compatibility bit 0 is 0, expecting 1 for PCI device

Now modify the SpcrAcpi for following:
1. Disable the support of PC-AT compatible IRQ support.
   Now only support IO-APIC interrupt type.
2. Set irq to 0.
3. Set the GSI to the value read from PCI device cfg space 0x3C.
4. Set PCI Flags to 1.

Cc: Isaac Oram <isaac.w.oram@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Signed-off-by: Ming Tan <ming.tan@intel.com>
Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>
Reviewed-by: Abdul Lateef Attar <abdattar@amd.com>