python-smartpm: add dependency on python-pprint

python-smartpm: add dependency on python-pprint

smart's "config" command uses the Python pprint module. If it is not
present, "config" fails with this error:

 #############
 # smart config --help
 error: Invalid command 'config'
 #############

This patch adds a dependency on python-pprint which fixes the error.
Tested on qemux86/core-image-sato-sdk.

[YOCTO #3643]

Signed-off-by: Bogdan Marinescu <bogdan.a.marinescu@intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>