galileo: Fix newlib-syscalls issue in Makefile
galileo: Fix newlib-syscalls issue in Makefile

This patch removes 'newlib-syscalls.c' from CONTIKI_SOURCEFILES variable
and appends it to PROJECT_SOURCEFILES. This way the buildsystem will
automatically consider the newlib-syscalls object code during linking
time.

arurke/contiki,MohamedSeliem/contiki,MohamedSeliem/contiki,arurke/contiki,arurke/contiki,MohamedSeliem/contiki,MohamedSeliem/contiki,MohamedSeliem/contiki,arurke/contiki,MohamedSeliem/contiki,arurke/contiki,arurke/contiki,MohamedSeliem/contiki,arurke/contiki