Simple steps to cross-build Debian Kernel package. The following steps confirmed working under Stretch.

Install Cross-Build Dependency

apt install fakeroot git kernel-wedge quilt ccache crossbuild-essential-<ARCH>

BTW. The following ARCH support cross-build explained here.

# apt-cache search crossbuild-essential-
crossbuild-essential-arm64 - Informational list of cross-build-essential packages
crossbuild-essential-armel - Informational list of cross-build-essential packages
crossbuild-essential-armhf - Informational list of cross-build-essential packages
crossbuild-essential-mipsel - Informational list of cross-build-essential packages
crossbuild-essential-powerpc - Informational list of cross-build-essential packages
crossbuild-essential-ppc64el - Informational list of cross-build-essential packages

Get DFSG tarball of Kernel

Simple way if it already reached archive:

wget http://httpredir.debian.org/debian/pool/main/l/linux/linux_4.8.15.orig.tar.xz

Other a few ways to get the pristine tarball of upstream linux kernel:

Clone Git Repo of Debian Kernel

git clone -n https://anonscm.debian.org/git/kernel/linux.git debian-kernel
cd debian-kernel
# list all tags
git tag -l
# starting from a release is a good idea
git checkout -b sid debian/4.8.15-1

Cross Build

Take ARM/armel, flavour marvell as example.

export $(dpkg-architecture -aarmel)
export PATH=/usr/lib/ccache:$PATH
fakeroot make -f debian/rules clean
fakeroot make -f debian/rules orig
fakeroot make -f debian/rules source
fakeroot make -f debian/rules.gen setup_armel_none_marvell
fakeroot make -f debian/rules.gen binary-arch_armel_none_marvell binary-indep


CategoryKernel