package_deb.bbclass: fix 'armel' override

package_deb.bbclass: fix 'armel' override

The 'armel' override for DKPG_ARCH was causing the meta-toolchain
build to fail. The assignment was moved to an anonymous fragment
of Python code, so it doesn't affect the assignments in
cross-canadian.bbclass anymore, thus fixing the issue.

[YOCTO #4080]

(From OE-Core rev: 6f86fe5d66e401377bccd9f635270033b99a9f4b)

Signed-off-by: Bogdan Marinescu <bogdan.a.marinescu@intel.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>