scripts/config: fix assignment of parameters for short version of --*-after options

When --*-after options are used, two parameters are parsed from the
command-line before the adequate function is called:
  - the `before' option, after which the new option will be inserted,
  - the name of the option to enable/disable/modularise.

With the short version of --*-after options (namely -E, -D, -M), the
parsing step is not performed which leads to processing unset variables.

Add options -E, -D, -M to the test that triggers assignment of parameters
for --*-after options.

Signed-off-by: Clement Chauplannaz <chauplac@gmail.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>