ppc: remove -ffixed-r14 gcc option.

This is no loger needed, free up r14 for general usage.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
diff --git a/cpu/mpc83xx/config.mk b/cpu/mpc83xx/config.mk
index d619426..e80919b 100644
--- a/cpu/mpc83xx/config.mk
+++ b/cpu/mpc83xx/config.mk
@@ -20,7 +20,7 @@
 # MA 02111-1307 USA
 #
 
-PLATFORM_RELFLAGS += -fPIC -ffixed-r14 -meabi
+PLATFORM_RELFLAGS += -fPIC -meabi
 
 PLATFORM_CPPFLAGS += -DCONFIG_MPC83xx -DCONFIG_E300 \
 			-ffixed-r2 -msoft-float