Allow defining multiple GCC O Levels 2/2

Change-Id: Idac74b61ece0f9fdc35b29188ec4c5191ebfcae2
Rework if statements for GCC Level. [1/2]

Reworked the if statements to give only 2 options, either Os or O3. If neither one of them is selected as an option, it will select the default Optimization Level which is O2.

PS2: Update commit message
PS3: Rebase and ready for merge

Change-Id: I64d5787bc86242fd613eb3931cd9bd46d7f17c49
Signed-off-by: Lokesh Chamane <lokesh.c703@gmail.com>
The GCC Optimization Levels AGAIN [1/2]

So after lurking around, I found out that we didn't set up the GCC Optimization
Levels to the TARGET_linux_mips.mk and I also found out that the Global Cflags
for TARGET_linux-x86.mk uses O2 in by default. Now I added those GCC
Optimization Levels to it but I'm not sure if they work? ¯\_(ツ)_/¯

PS2: Tabs.
PS3: Update the commit message..
PS4: DONE UPDATING THE COMMIT MESSAGE!

Change-Id: Ibd9e0b5580bdd4d9a865741d856486c35ca1f7f6
Signed-off-by: Lokesh Chamane <lokesh.c703@gmail.com>
Merge branch 'cm-10.2' of github.com:PAC-man/android_build into PAC-man-cm-10.2

Conflicts:
	core/combo/TARGET_linux-arm.mk
	core/combo/select.mk