target-sh4: switch sh4 to softfloat

We need to be able to catch exceptions correctly and thus enable softfloat
on SH4.

As all machines except i386 and x86_64 are using softfloat, make it the
default and change the case to detect i386 and x86_64. Note that CRIS
doesn't have an FPU, so it can be configured with both softfloat-native
and softfloat.
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>

configure

@@ -3061,11 +3061,11 @@ if test ! -z "$gdb_xml_files" ; then
 fi
 
 case "$target_arch2" in
-  alpha|arm|armeb|m68k|microblaze|mips|mipsel|mipsn32|mipsn32el|mips64|mips64el|ppc|ppc64|ppc64abi32|ppcemb|s390x|sparc|sparc64|sparc32plus)
-    echo "CONFIG_SOFTFLOAT=y" >> $config_target_mak
+  i386|x86_64)
+    echo "CONFIG_NOSOFTFLOAT=y" >> $config_target_mak
     ;;
   *)
-    echo "CONFIG_NOSOFTFLOAT=y" >> $config_target_mak
+    echo "CONFIG_SOFTFLOAT=y" >> $config_target_mak
     ;;
 esac