toolchain/wrapper: fix code style

The header of the .mk file fits in one line, so rearrange it to be
similar to a header from a package.

Signed-off-by: Ricardo Martincoski <ricardo.martincoski@gmail.com>
Cc: Thomas De Schampheleire <thomas.de_schampheleire@nokia.com>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

toolchain/toolchain-wrapper.mk

@@ -1,4 +1,8 @@
-# This file contains the definition of the toolchain wrapper build commands
+################################################################################
+#
+# definition of the toolchain wrapper build commands
+#
+################################################################################
 
 # We use --hash-style=both to increase the compatibility of the generated
 # binary with older platforms, except for MIPS, where the only acceptable