lib: elf: Move the generic elf loading/validating functions to lib

Move the generic elf loading/validating functions to lib/
so that they can be re-used and accessed by code existing
outside cmd.

While at it remove the duplicate static version of load_elf_image_phdr
under arch/arm/mach-imx/imx_bootaux.c.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Suggested-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
Reviewed-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
diff --git a/lib/Makefile b/lib/Makefile
index 15259d0..32bf3f3 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -122,6 +122,7 @@
 endif
 
 obj-y += date.o
+obj-$(CONFIG_LIB_ELF) += elf.o
 
 #
 # Build a fast OID lookup registry from include/linux/oid_registry.h