package/cifs-utils: bump version to 6.12

package/cifs-utils: bump version to 6.12

- removed 0001-Use-DESTDIR-when-installing-mount.smb3-and-optionall.patch
  (superseded by upstream commit [1])

- adjust autoreconf comment accordingly

- add option for smb tools to avoid hard python runtime dependency
  (smbinfo and smb2-quota are python scripts)

Changelog ([2]):

  December, 2020: Release 6.12
  get/setcifsacl tools are improved to support changing owner, group and SACLs
  mount.cifs is enhanced to use SUDO_UID env variable for cruid
  smbinfo is re-written in Python language
  https://lists.samba.org/archive/samba-technical/2020-December/136156.html

[1] https://git.samba.org/?p=cifs-utils.git;a=patch;h=a00e84378d9c5e63272ff69ca18fd0e872b384d3
[2] https://wiki.samba.org/index.php/LinuxCIFS_utils

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>