cmake/modules/config_sysconfig: Allow configuration of sysconfig module
cmake/modules/config_sysconfig: Allow configuration of sysconfig module

Checking whether the host system has /etc/sysconfig is not deterministic
when cross compiling. Allow this to be disabled by adding a configure
option for it. OpenEmbedded can set this and have deterministic build
output independent of the host OS.

Signed-off-by: Richard Purdie <3b7a1db6efedd40440bc6443bf377195011524e5@linuxfoundation.org>

libproxy/libproxy,libproxy/libproxy,libproxy/libproxy,libproxy/libproxy,libproxy/libproxy,libproxy/libproxy,libproxy/libproxy