arc770: fix broken upstream change

Add a patch to revert upstream commit 9aed02feae57bf7a40cb04ea0e3017cb7a998db4
which introduces syntax errors.

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

target/linux/arc770/patches-4.4/900-revert-unaligned-access-delay-corner-case.patch

@@ -0,0 +1,31 @@
+From: Jo-Philipp Wich <jo@mein.io>
+Date: Tue, 7 Feb 2017 09:26:00 +0100
+Subject: [PATCH] arc: revert broken upstream change
+
+The upstream commit
+"9aed02f ARC: [arcompact] handle unaligned access delay slot corner case"
+introduced a syntax error in arch/arc/kernel/unaligned.c, leading to the
+following build failure:
+
+    arch/arc/kernel/unaligned.c: In function 'misaligned_fixup':
+    arch/arc/kernel/unaligned.c:246:25: error: expected ';' before '~' token
+       regs->ret = regs->bta ~1U;
+                         ^
+    make[6]: *** [arch/arc/kernel/unaligned.o] Error 1
+
+This patch reverts the offending change until an upstream fix is available.
+
+Signed-off-by: Jo-Philipp Wich <jo@mein.io>
+--- a/arch/arc/kernel/unaligned.c
++++ b/arch/arc/kernel/unaligned.c
+@@ -241,9 +241,8 @@ int misaligned_fixup(unsigned long addre
+ 	if (state.fault)
+ 		goto fault;
+ 
+-	/* clear any remanants of delay slot */
+ 	if (delay_mode(regs)) {
+-		regs->ret = regs->bta ~1U;
++		regs->ret = regs->bta;
+ 		regs->status32 &= ~STATUS_DE_MASK;
+ 	} else {
+ 		regs->ret += state.instr_len;