BlSupportPei: prevent lower coreboot table from being overwritten

Exclude the bottom 4kb from being included in System Memory HoB

UefiPayloadPkg/BlSupportPei/BlSupportPei.c

@@ -406,8 +406,8 @@ BlPeiEntryPoint (
     EFI_RESOURCE_ATTRIBUTE_WRITE_THROUGH_CACHEABLE |
     EFI_RESOURCE_ATTRIBUTE_WRITE_BACK_CACHEABLE
     ),
-    (EFI_PHYSICAL_ADDRESS)(0),
-    (UINT64)(0xA0000)
+    (EFI_PHYSICAL_ADDRESS)(0 + 0x1000),
+    (UINT64)(0xA0000 - 0x1000)
     );
 
   BuildResourceDescriptorHob (