package/pkg-generic.mk: Remove Info documents dir entry

package/pkg-generic.mk: Remove Info documents dir entry

Some packages (autotools for instance) install documentation
files using install-info. This program adds an entry in
the Info directory file (share/info/dir) and this causes
TARGET_DIR and/or HOST_DIR overwrite.

In order to avoid this overwrite this patch removes the Info
directory file right after any installation.

In order to be as generic as possible, this patch introduces
a new tooling to remove useless and conflicting files based
on the file and/or directory list <PKG>_DROP_FILES_OR_DIRS.
share/info/dir file is added for every packages in this list.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
[yann.morin.1998@free.fr:
  - don't expand when nothing to remove
  - do not add '/' between $(1) and % as files' paths are
    already absolute
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>