Optimize Clang

* Use -O3 and disable warnings.
* Make it optional so device maintainers can choose if they want to use it or not.

Signed-off-by: Chet Kener <Cl3Kener@gmail.com>
Change-Id: I984f428022a68a825aa041866e8d459bd6511f72
Add Linker Optimizations

* Make these optional as well as the Clang optimizations.
* Enable using OPTIMIZE_LINKER=y to BoardConfig of your device.

Signed-off-by: Chet Kener <Cl3Kener@gmail.com>
Change-Id: I984f428022a68a825aa041866e8d456bd6411f79
Revert "Optimize Clang"

This reverts commit 5e41f9f715bd71b85f582bee72afca6e8385368e.

Change-Id: I6edbe08822fed910ce6455fe7c4564c166a0ce75
Merge remote-tracking branch 'ls/kitkat'

Signed-off-by: Chet Kener <Cl3Kener@gmail.com>

Conflicts:
	core/combo/select.mk