This adds a number of options to config/Config-kernel.in so that
packages related to SELinux support can enable the appropriate Linux
kernel support.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
[rebase; add ext4, F2FS, UBIFS, and JFFS2 support; add commit message]
Signed-off-by: W. Michael Petullo <mike@flyn.org>