mksh: new package

The MirOS Korn Shell is a quite complete posix shell implementation,
is rather small and supports vi mode properly.

[Peter: use mksh.1 as license file, use TARGET_CONFIGURE_OPTS, install -D]
Signed-off-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be>
Signed-off-by: Waldemar Brodkorb <wbx@openadk.org>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
diff --git a/package/Config.in b/package/Config.in
index fe3ac2c9..ef82b2e 100644
--- a/package/Config.in
+++ b/package/Config.in
@@ -1655,6 +1655,7 @@
 comment "Shells"
 	source "package/bash/Config.in"
 	source "package/dash/Config.in"
+	source "package/mksh/Config.in"
 	source "package/zsh/Config.in"
 comment "Utilities"
 	source "package/at/Config.in"