Thanks to some recent config changing, debugconfig/arm/armv7 was
removed. Remove this file from config generation as well. It should be
added back later if necessary.
The existing method of managing configuration files gets unweildy.
Changing individual lines in text files gets difficult without
manual organization. Switch to a method of configuration generation
that's inspired from the method used inside Red Hat. Each configuration
option gets its own file which are then combined to form the
configuration files. This makes confirming what's actually enabled much
easier.