Remove SaberMod arm-eabi

Having build issues on random rigs, with the statement that vendor/samsung has uncommitted
changes.
rm -rf prebuilts/gcc/linux-x86/arm/arm-eabi-4.8 before repo sync should resolve this.

Credits to arrrghhh.

Change-Id: Ie827182726c7f0962f31df489221a1ab801ac0f8