Fix makefile compiler

  This keeps it from bitching at us that it can't find the
  referenced compiler.

Signed-off-by: KhasMek <Boushh@gmail.com>
g18: set matricom_g18_defconfig as default

  I'm so sick of it using /boot/$config instead of the
  only one we use on 4.2.2. Let's set it as default so
  I don't have to manually load it up on every
  make menuconfig.

Signed-off-by: KhasMek <Boushh@gmail.com>