linker: New sources to manage the ELF program header table.

This patch introduces two new source files containing a set of functions
to manage the program header table in an ELF binary, including the ability
to load PT_LOAD segments, and apply PT_GNU_RELRO protection.

Note: the files are not used currently, this will appear in a series
      of future patches that will gradually modify linker.c to use
      the phdr_table_xxx functions properly.

Change-Id: Ia3d4c1ff5fc3e265d8258b64b492f4e643f51bdc
diff --git a/linker/Android.mk b/linker/Android.mk
index 2f39cbe..a739b4f 100644
--- a/linker/Android.mk
+++ b/linker/Android.mk
@@ -6,6 +6,7 @@
 	linker.c \
 	linker_environ.c \
 	linker_format.c \
+	linker_phdr.c \
 	rt.c \
 	dlfcn.c \
 	debugger.c