package/libffi: bump to version 3.4.2

package/libffi: bump to version 3.4.2

- Use official tarball
- Drop fourth to seventh patches (already in version)
- Update hash of LICENSE file (update in year:
  https://github.com/libffi/libffi/commit/2bdc8e52efb78d939f23efb4f9c515355610bff5
  https://github.com/libffi/libffi/commit/b844a9c7f1ca792a1dfb0c09d5dae576178e6729)
- Update indentation in hash file (two spaces)

https://github.com/libffi/libffi/blob/v3.4.2/README.md

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>