target/avr: Add missing includes of qemu/error-report.h

This had been pulled in from tcg/tcg.h, via exec/cpu_ldst.h,
via exec/exec-all.h, but the include of tcg.h will be removed.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/target/avr/helper.c b/target/avr/helper.c
index 156dde4..2bad242 100644
--- a/target/avr/helper.c
+++ b/target/avr/helper.c
@@ -20,6 +20,7 @@
 
 #include "qemu/osdep.h"
 #include "qemu/log.h"
+#include "qemu/error-report.h"
 #include "cpu.h"
 #include "hw/core/tcg-cpu-ops.h"
 #include "exec/exec-all.h"