scripts/template_dir: -[no]cmake flag for CMake module installation

There are two issues with CMake module installation that are
problematic for distro packages:
1. the cmake module is installed under $HOME and this path is not overridable
2. the path to SDK recorded in the cmake file is the same as the
target directory, which might be prefixed by the staging path of the
package build (e.g.  ~/mypackages/zerphyr-sdk/destdir/opt/zerphyr-sdk),
not the final installation directory in the system (/opt/zephyr-sdk).

1 is fixable by making the variable overridable from the environment:
    : ${ZEPHYR_SDK_REGISTRY_DIR:=$HOME/.cmake/packages/Zephyr-sdk}
(but this may be a bashism). But, 1 is not useful unless 2 is also
addressed.

2 might be fixable by introducing a prefix argument -p (default "") in
addition to the target_dir (-d), and composing the destination directory
for copying files as $prefix/$target_dir while using only $target_dir
wherever installation paths are written, such as in the CMake module.

Until 1 or 2 are addressed, add -[no]cmake arg so that the package
scripts can install the CMake module themselves.

Author: alexeicolin

scripts/template_dir

@@ -3,6 +3,7 @@ target_sdk_dir=""
 post_install_cleanup=1
 confirm=0
 rc_confirm=""
+cmake_confirm=""
 
 usage () {
   cat << EOF
@@ -22,6 +23,9 @@ Options:
   -[no]rc
         Whether to create/update the ~/.zerphyrc file (prompt if not given)
 
+  -[no]cmake
+        Whether to install Zephyr-sdk CMake module (prompt if not given)
+
 EOF
 }
 
@@ -69,13 +73,22 @@ while [ "$1" != "" ]; do
 			if [ -z "$rc_confirm" ]; then
 			  rc_confirm="y"
 			fi
+			if [ -z "$cmake_confirm" ]; then
+			  cmake_confirm="y"
+			fi
 			;;
 		-rc )
 			rc_confirm="y";
 			;;
 		-norc )
 			rc_confirm="n";
 			;;
+		-cmake )
+			cmake_confirm="y"
+			;;
+		-nocmake )
+			cmake_confirm="n"
+			;;
 		* )
 			echo "Error: Invalid argument \"$1\""
 			usage
@@ -158,8 +171,11 @@ do_cmake_package()
 			return
 		fi
 
-		query "registering Zephyr-sdk CMake module with path $target_sdk_dir "
-		if [ "$answer" = "y" ]; then
+		if [ -z "$cmake_confirm" ]; then
+			prompt "registering Zephyr-sdk CMake module with path $target_sdk_dir "
+			cmake_confirm=$answer
+		fi
+		if [ "$cmake_confirm" = "y" ]; then
 			if [ ! -d $ZEPHYR_SDK_REGISTRY_DIR ]; then
 				mkdir -p $ZEPHYR_SDK_REGISTRY_DIR
 			fi