ARM: enable elf_fdpic on systems with an MMU

Provide the necessary changes to be able to execute ELF-FDPIC binaries
on ARM systems with an MMU.

The default for CONFIG_BINFMT_ELF_FDPIC is also set to n if the regular
ELF loader is already configured so not to force FDPIC support on
everyone. Given that CONFIG_BINFMT_ELF depends on CONFIG_MMU, this means
CONFIG_BINFMT_ELF_FDPIC will still default to y when !MMU.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Acked-by: Mickael GUENE <mickael.guene@st.com>
Tested-by: Vincent Abriou <vincent.abriou@st.com>
Tested-by: Andras Szemzo <szemzo.andras@gmail.com>
diff --git a/arch/arm/include/asm/mmu.h b/arch/arm/include/asm/mmu.h
index e0eb166..bdec37c 100644
--- a/arch/arm/include/asm/mmu.h
+++ b/arch/arm/include/asm/mmu.h
@@ -14,6 +14,10 @@ typedef struct {
 #ifdef CONFIG_VDSO
 	unsigned long	vdso;
 #endif
+#ifdef CONFIG_BINFMT_ELF_FDPIC
+	unsigned long	exec_fdpic_loadmap;
+	unsigned long	interp_fdpic_loadmap;
+#endif
 } mm_context_t;
 
 #ifdef CONFIG_CPU_HAS_ASID