x86: MMU: Generation of PAE tables

If CONFIG_X86_PAE_MODE is enabled for the build, then gen_mmu.py
would generate the boot time page tables in PAE format.
This supports 3 level paging i.e Page Directory Pointer(PDPT), Page
Directory(PD) and Page Table(PT). Each Page Table Entry(PTE) maps to
a 4KB region. Each Page Directory Entry(PDE) maps a 2MB region.
Each Page Directory Pointer Entry(PDPTE) maps to a 1GB region.

JIRA: ZEP-2511

Signed-off-by: Adithya Baglody <adithya.nagaraj.baglody@intel.com>

arch/x86/Makefile.mmu

@@ -13,7 +13,8 @@ quiet_cmd_gen_mmu = GMMU    $@
       cmd_gen_mmu =								\
 (										\
 	$(OBJCOPY) -I $(OUTPUT_FORMAT)  -O binary -j mmulist $< mmulist.bin &&	\
-	$(GENMMU) -i mmulist.bin -o mmu_tables.bin $(GENMMU_EXTRA_ARGS)\
+	$(GENMMU) -i mmulist.bin -k $(PREBUILT_KERNEL)                      	\
+		  -o mmu_tables.bin $(GENMMU_EXTRA_ARGS)                 	\
 )