config: set architecture TARGET_FEATURES in config/arch.ARCH

Should PROJECT or DEVICE options set TARGET_FEATURES, tack them on
instead of overwriting them.

Signed-off-by: Ian Leonard <antonlacon@gmail.com>

config/arch.aarch64

@@ -3,6 +3,13 @@
     TARGET_CPU=cortex-a53
   fi
 
+  # 64bit userland and neon required by armv8
+  if [ -z "${TARGET_FEATURES}" ]; then
+    TARGET_FEATURES="64bit neon"
+  else
+    TARGET_FEATURES+=" 64bit neon"
+  fi
+
 # TARGET_CPU:
 # generic cortex-a35 cortex-a53 cortex-a57 cortex-a72
 # exynos-m1 qdf24xx thunderx xgene1 cortex-a57.cortex-a53
@@ -14,7 +21,6 @@
       TARGET_SUBARCH=aarch64
       TARGET_VARIANT=armv8-a
       TARGET_ABI=eabi
-      TARGET_FEATURES+=" neon"
       ;;
   esac
 

config/arch.arm

@@ -3,6 +3,13 @@
     TARGET_CPU=cortex-a8
   fi
 
+  # 32bit userland
+  if [ -z "${TARGET_FEATURES}" ]; then
+    TARGET_FEATURES="32bit"
+  else
+    TARGET_FEATURES+=" 32bit"
+  fi
+
 # TARGET_CPU:
 # arm2 arm250 arm3 arm6 arm60 arm600 arm610 arm620 arm7 arm7m arm7d
 # arm7dm arm7di arm7dmi arm70 arm700 arm700i arm710 arm710c

config/arch.x86_64

@@ -3,6 +3,13 @@
     TARGET_CPU=core2
   fi
 
+  # 64bit userland
+  if [ -z "${TARGET_FEATURES}" ]; then
+    TARGET_FEATURES="64bit"
+  else
+    TARGET_FEATURES+=" 64bit"
+  fi
+
 # determine architecture's family
   TARGET_SUBARCH=x86_64