kernel: Strip modules

kernel: Strip modules

The kernel does not strip modules by default. This can be enabled by
passing INSTALL_MOD_STRIP=1 when installing the modules.

Since we are not actually building the kernel with debuginfo and we are
comressing the modules afterwards, there is not a huge saving on disk
space, but there is a small saving of memory when loading the modules.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>