cli11: Remove dev pkg dep to main pkg

cli11 is header-only and the main package is empty.  Remove the
dependency to cli11 from cli11-dev so cli11-dev can be included in an
SDK via IMAGE_INSTALL, RDEPENDS, and the like.

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-support/cli11/cli11_1.8.0.bb

@@ -17,3 +17,6 @@ inherit ptest
 
 EXTRA_OECMAKE += "-DCLANG_TIDY=OFF"
 DEPENDS += "boost"
+
+# cli11 is a header only C++ library, so the main package will be empty.
+RDEPENDS_${PN}-dev = ""