helper: add align.h

OpenOCD has to often align values or check for alignment.
Use a dedicated set of macros instead of reinventing the wheel
each time.

Change-Id: Ia58711608aae0801deeaccb5f33148f2073b0bbd
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/6374
Tested-by: jenkins
Reviewed-by: Tarek BOCHKATI <tarek.bouchkati@gmail.com>

src/helper/Makefile.am

@@ -15,6 +15,7 @@ noinst_LTLIBRARIES += %D%/libhelper.la
 	%D%/util.c \
 	%D%/jep106.c \
 	%D%/jim-nvp.c \
+	%D%/align.h \
 	%D%/binarybuffer.h \
 	%D%/bits.h \
 	%D%/configuration.h \