Add configuration for toolchains without libm

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@517 42af7a65-404d-4744-a932-0658087f49c3

configs/pjrc-8051/defconfig

@@ -82,6 +82,16 @@ CONFIG_SWITCH_FRAME_DUMP=n
 CONFIG_INTERRUPT_FRAME_DUMP=n
 CONFIG_LED_DEBUG=n
 
+#
+# General build options
+#
+# CONFIG_RRLOAD_BINARY - make the rrload binary format used with
+#   BSPs from www.ridgerun.com
+# CONFIG_HAVE_LIBM - toolchain supports libm.a
+#
+CONFIG_RRLOAD_BINARY=n
+CONFIG_HAVE_LIBM=n
+
 #
 # General OS setup
 #
@@ -178,14 +188,6 @@ CONFIG_ARCH_KMALLOC=n
 CONFIG_ARCH_KZMALLOC=n
 CONFIG_ARCH_KFREE=n
 
-#
-# General build options
-#
-# CONFIG_RRLOAD_BINARY - make the rrload binary format used with
-#   BSPs from www.ridgerun.com
-#
-CONFIG_RRLOAD_BINARY=n
-
 #
 # Sizes of configurable things (0 disables)
 #