pkg-utils: update comments after renaming of package infra macros

The package infrastructure macros have a long time ago been renamed
from GENTARGETS, AUTOTARGETS to generic-package and
autotools-package. However, one comment in pkg-utils.mk keeps a
reference to these *TARGETS macros. This commit updates this comment
to match the new name of these macros.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: "Yann E. MORIN" <yann.morin.1998@free.fr>

package/pkg-utils.mk

@@ -60,7 +60,7 @@ endef
 
 # Helper functions to determine the name of a package and its
 # directory from its makefile directory, using the $(MAKEFILE_LIST)
-# variable provided by make. This is used by the *TARGETS macros to
+# variable provided by make. This is used by the *-package macros to
 # automagically find where the package is located.
 pkgdir = $(dir $(lastword $(MAKEFILE_LIST)))
 pkgname = $(lastword $(subst /, ,$(pkgdir)))