arm: enable unified assembly syntax in more files

This makes these files compileable, or in some cases less
broken, on Cortex-M targets.

In lcd-16bit.c, newer versions of GAS complain about the
infix condition codes so we use the suffix form instead,
which requires unified syntax to compile on GCC 4.9.

Change-Id: If45166d3fc83d64c692cbb331096a966397aa9e9

lib/rbcodec/codecs/demac/libdemac/predictor-arm.S

@@ -23,6 +23,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
 */
 #include "demac_config.h"
 
+    .syntax     unified
     .section    ICODE_SECTION_DEMAC_ARM,"ax",%progbits
 
     .align      2