scripts: Add coccinelle file to use BIT macro

scripts/coccinelle/bit-macro.cocci

@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-3.0-only
+// Replace shifts with BIT macro
+
+@@ expression val; @@
+-(1 << val)
++BIT(val)
+
+@@ expression val; @@
+-(1U << val)
++BIT(val)
+
+@@ expression val; @@
+-1 << val
++BIT(val)

scripts/coccinelle/macros.h

@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-3.0-only
+// SDCC extenstions that need to be defined away for spatch
+
+#define __at(x)
+#define __code
+#define __critical
+#define __data
+#define __reentrant
+#define ___

scripts/spatch.sh

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-3.0-only
+
+spatch \
+    --sp-file ./scripts/coccinelle/bit-macro.cocci \
+    --macro-file ./scripts/coccinelle/macros.h \
+    --no-includes \
+    --include-headers \
+    --preprocess \
+    --in-place \
+    --dir src/