soc/intel/xeon_sp/cpx: use HOB_TYPE_GUID_EXTENSION to interpret platform HOBs

Platform HOBs (in particular IIO_UDS and MemoryMap HOBs) are of HOB type
HOB_TYPE_GUID_EXTENSION, therefore they do not have resource structure.

Remove the erroneous code related to resource structure.

Remove unnecessary function prototypes from header files, and define them
as static in hob_display.c.

Since we have the HOB pointer, there is not need to search HOB by GUID.
Remove unnecessary calling of fsp_find_extension_hob_by_guid().

Signed-off-by: Jonathan Zhang <jonzhang@fb.com>
Signed-off-by: Reddy Chagam <anjaneya.chagam@intel.com>
Change-Id: Ib99bce39e6eb2aeb95242dfba36774653bbe91fd
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43335
Reviewed-by: Christian Walter <christian.walter@9elements.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/vendorcode/intel/fsp/fsp2_0/cooperlake_sp/hob_memmap.h

@@ -109,6 +109,4 @@ typedef struct SystemMemoryMapHob {
 
 #pragma pack()
 
-void soc_display_memmap_hob(void);
-
 #endif