lrdp-v2: Add lowmem page address retrieving for ARM32

memstart_addr is now used by lrdp-v2 to retrieve lowmem page
address, but the variable is only defined on ARM64. Add code for
retrieving the same information on ARM32

Change-Id: I825b318962751b1b948df9cb948149e47e3fdf50

linux-ramdump-parser-v2/mm.py

@@ -271,8 +271,11 @@ def dont_map_hole_lowmem_page_address(ramdump, page):
 
 def normal_lowmem_page_address(ramdump, page):
     phys = page_to_pfn(ramdump, page) << 12
-    memstart_addr = ramdump.read_s64('memstart_addr')
-    return phys - memstart_addr + ramdump.page_offset
+    if ramdump.arm64:
+        memstart_addr = ramdump.read_s64('memstart_addr')
+        return phys - memstart_addr + ramdump.page_offset
+    else:
+        return phys - ramdump.phys_offset + ramdump.page_offset
 
 
 def lowmem_page_address(ramdump, page):