Remove aarch32 build from build-tool

* Removing support for aarch32 builds from the
  build-tool as Arm NN is dropping support for
  this target architecture.
* Fixed missing additional ACL scons params in
  ACL build.

Change-Id: Ib18b3286ce18d169ce8d8af2bd9b5d54f110eb3b
Signed-off-by: James Conroy <james.conroy@arm.com>
diff --git a/build-tool/scripts/validation.sh b/build-tool/scripts/validation.sh
index 785c1b8..7928952 100755
--- a/build-tool/scripts/validation.sh
+++ b/build-tool/scripts/validation.sh
@@ -20,8 +20,8 @@
   exit 1
 fi
 
-if [ "$target_arch" != "aarch64" ] && [ "$target_arch" != "aarch32" ] && [ "$target_arch" != "x86_64" ]; then
-  echo "$name: --target-arch is not valid. Valid options are: aarch64, aarch32, x86_64"
+if [ "$target_arch" != "aarch64" ] && [ "$target_arch" != "x86_64" ]; then
+  echo "$name: --target-arch is not valid. Valid options are: aarch64, x86_64"
   exit 1
 fi
 
@@ -32,13 +32,6 @@
   fi
 fi
 
-if [ "$target_arch" == "aarch32" ]; then
-  if [ "$HOST_ARCH" != "x86_64" ]; then
-    echo "$name: aarch32 is the only supported --target_arch when host is x86_64 (cross compile only)"
-    exit 1
-  fi
-fi
-
 # Validation of chosen Arm NN dependencies
 if [ "$flag_tflite_delegate" -eq 0 ] && [ "$flag_tflite_parser" -eq 0 ] && [ "$flag_onnx_parser" -eq 0 ]; then
   echo "$name: at least one of flags --tflite-delegate, --tflite-parser or --onnx-parser must be set (or --all)."