Kernel : Use Linaro 4.7.4 Toolchain

Change-Id: Iac0e1deb2f030b283c9dc858d290552b345d4689
Rom : Use Linaro 4.8 Toolchain // Use -O3 for Optimization

Change-Id: I2536a57ef644a17a3fb06aeaca420a1fda43f224
Disable -Wunused-parameter

Change-Id: I4289c7d97d1d9694dd74f23d2e0fee07d2374e67
Hide more warnings

Change-Id: I6d7876b302edde0ec6de6b03b8aa71cdfff86a80