cmake: scripts: add 'winpty' support when available

Some Python scripts need to access to the underlying OS, like
using redirections. These interactions go through TTY interface.
On MinGW, these interactions/interfaces are called 'winpty'.
=> use them when available (harmless on platform *NIX platforms)

Signed-off-by: Cedric Lescop <cedric.lescop@se.com>

cmake/modules/FindHostTools.cmake

@@ -65,6 +65,12 @@ find_program(BOSSAC bossac)
 # in the mcuboot repository if that's present in some cases)
 find_program(IMGTOOL imgtool)
 
+# winpty is an optional dependency
+find_program(PTY_INTERFACE winpty)
+if("${PTY_INTERFACE}" STREQUAL "PTY_INTERFACE-NOTFOUND")
+  set(PTY_INTERFACE "")
+endif()
+
 # Default to the host system's toolchain if we are targeting a host based target
 if((${BOARD_DIR} MATCHES "boards\/native") OR ("${ARCH}" STREQUAL "posix")
    OR ("${BOARD}" STREQUAL "unit_testing"))

cmake/modules/kconfig.cmake

@@ -226,6 +226,7 @@ foreach(kconfig_target
     "SHIELD_AS_LIST=${SHIELD_AS_LIST_ESCAPED}"
     DTS_POST_CPP=${DTS_POST_CPP}
     DTS_ROOT_BINDINGS=${DTS_ROOT_BINDINGS}
+    ${PTY_INTERFACE}
     ${PYTHON_EXECUTABLE}
     ${EXTRA_KCONFIG_TARGET_COMMAND_FOR_${kconfig_target}}
     ${KCONFIG_ROOT}