python-{asn1crypto,evdev,lxml}: add -src packages

They seem to have become popular, so adding src packages for these as well.
Not bumping PKG_RELEASE intentionally, since these packages are new.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

lang/python/python-asn1crypto/Makefile

@@ -61,5 +61,8 @@ endef
 
 $(eval $(call PyPackage,python-asn1crypto))
 $(eval $(call BuildPackage,python-asn1crypto))
+$(eval $(call BuildPackage,python-asn1crypto-src))
+
 $(eval $(call Py3Package,python3-asn1crypto))
 $(eval $(call BuildPackage,python3-asn1crypto))
+$(eval $(call BuildPackage,python3-asn1crypto-src))

lang/python/python-evdev/Makefile

@@ -74,5 +74,8 @@ PYTHON_PKG_SETUP_GLOBAL_ARGS:=$(PYTHON3_PKG_SETUP_GLOBAL_ARGS)
 
 $(eval $(call PyPackage,python-evdev))
 $(eval $(call BuildPackage,python-evdev))
+$(eval $(call BuildPackage,python-evdev-src))
+
 $(eval $(call Py3Package,python3-evdev))
 $(eval $(call BuildPackage,python3-evdev))
+$(eval $(call BuildPackage,python3-evdev-src))

lang/python/python-lxml/Makefile

@@ -89,6 +89,8 @@ endef
 
 $(eval $(call PyPackage,python-lxml))
 $(eval $(call BuildPackage,python-lxml))
+$(eval $(call BuildPackage,python-lxml-src))
 
 $(eval $(call Py3Package,python3-lxml))
 $(eval $(call BuildPackage,python3-lxml))
+$(eval $(call BuildPackage,python3-lxml-src))