libcurl: drop curl* aliases

They're unused hence not useful.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/libcurl/libcurl.mk

@@ -67,8 +67,3 @@ LIBCURL_POST_INSTALL_TARGET_HOOKS += LIBCURL_TARGET_CLEANUP
 endif
 
 $(eval $(autotools-package))
-
-curl: libcurl
-curl-clean: libcurl-clean
-curl-dirclean: libcurl-dirclean
-curl-source: libcurl-source