libgcc-4.5: Fix nativesdk build problem

We need to use BPN instead of PN so we
access libgcc and not libgcc-nativesdk

Signed-off-by: Khem Raj <raj.khem@gmail.com>
Tested-by: Denys Dmytriyenko <denys@ti.com>
Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>