package/python-mbstrdecoder: add python-chardet dependency

chardet is a mandatory runtime dependency since version 0.8.2 and
https://github.com/thombashi/mbstrdecoder/commit/e9344a0916f65d143c51e0680c30db4ae7690ccf

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/python-mbstrdecoder/Config.in

@@ -1,6 +1,7 @@
 config BR2_PACKAGE_PYTHON_MBSTRDECODER
 	bool "python-mbstrdecoder"
 	depends on BR2_PACKAGE_PYTHON3
+	select BR2_PACKAGE_PYTHON_CHARDET # runtime
 	help
 	  multi-byte character string decoder.