ANDROID: android-base.cfg: add CONFIG_IKCONFIG option

This adds CONFIG_IKCONFIG and CONFIG_IKCONFIG_PROC options, which are a
requirement for the O release.

Bug: 35803310
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
(cherry picked from commit 7d9280f579ff0731facb1e10f32e4a88a07f33f8)