Add pentium-m to the list of tuning targets

Originally committed as revision 6627 to svn://svn.ffmpeg.org/ffmpeg/trunk

configure

@@ -1100,7 +1100,7 @@ if test $tune != "generic"; then
             TUNECPU=ppc970
             POWERPCMODE="64bits"
         ;;
-        i[3456]86|pentium|pentiumpro|pentium-mmx|pentium[234]|prescott|k6|k6-[23]|athlon|athlon-tbird|athlon-4|athlon-[mx]p|winchip-c6|winchip2|c3|nocona|athlon64|k8|opteron|athlon-fx)
+        i[3456]86|pentium|pentiumpro|pentium-mmx|pentium[234]|pentium-m|prescott|k6|k6-[23]|athlon|athlon-tbird|athlon-4|athlon-[mx]p|winchip-c6|winchip2|c3|nocona|athlon64|k8|opteron|athlon-fx)
             add_cflags "-march=$tune"
         ;;
         sparc64)