conf --silentoldconfig generates required autoconf.h file
but when invoked on modified Kconfig it will ask for user
input which breaks the build. To automatically regenerate
config structure and then autogenerate headers run
config --olddefconfig first.
Signed-off-by: NZbigniew Bodek <zbigniew.bodek@huawei.com>
Change-Id: If7f7653c80cc0c5c0d84015b8e50fcb66568d00a