cross-canadian: Let cross-canadian packages build for uclibc

cross-canadian: Let cross-canadian packages build for uclibc

Fixes errors like

Parsing recipes...ERROR: Building cross-candian powerpc for an unknown
TARGET_SYS (powerpc-angstrom-linux-uclibc), please update
cross-canadian.bbclass
ERROR: Building cross-candian powerpc for an unknown TARGET_SYS
(powerpc-angstrom-linux-uclibc), please update cross-canadian.bbclass

(From OE-Core rev: 7928a9e54dfa85cbfd042e25ed883a9795f09f1b)

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>