MIPS: Ensure ELF appended dtb is relocated

This fixes booting with the combination of CONFIG_RELOCATABLE=y
and CONFIG_MIPS_ELF_APPENDED_DTB=y.

Sections that appear after the relocation table are not relocated
on system boot (except .bss, which has special handling).

With CONFIG_MIPS_ELF_APPENDED_DTB, the dtb is part of the
vmlinux ELF, so it must be relocated together with everything else.

Fixes: 069fd766 ("MIPS: Reserve space for relocation table")
Signed-off-by: Yasha Cherikovsky <yasha.che3@gmail.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org # v4.7+

arch/mips/kernel/vmlinux.lds.S

@@ -140,6 +140,13 @@ SECTIONS
 	PERCPU_SECTION(1 << CONFIG_MIPS_L1_CACHE_SHIFT)
 #endif
 
+#ifdef CONFIG_MIPS_ELF_APPENDED_DTB
+	.appended_dtb : AT(ADDR(.appended_dtb) - LOAD_OFFSET) {
+		*(.appended_dtb)
+		KEEP(*(.appended_dtb))
+	}
+#endif
+
 #ifdef CONFIG_RELOCATABLE
 	. = ALIGN(4);
 
@@ -164,11 +171,6 @@ SECTIONS
 	__appended_dtb = .;
 	/* leave space for appended DTB */
 	. += 0x100000;
-#elif defined(CONFIG_MIPS_ELF_APPENDED_DTB)
-	.appended_dtb : AT(ADDR(.appended_dtb) - LOAD_OFFSET) {
-		*(.appended_dtb)
-		KEEP(*(.appended_dtb))
-	}
 #endif
 	/*
 	 * Align to 64K in attempt to eliminate holes before the