Move pthread and graphite modules list to vendor/psd (2/2)

Signed-off-by: Paul Beeler <pbeeler80@gmail.com>
Merge remote-tracking branch 'aospal/kitkat' into kitkat
hack our way into allowing gcc to be overrided in product makefile by using pa_product_hooks

also set hammerhead default to 4.10 for kernel
Move android toolchain overrides to the proper place
Make graphite and pthread work with vendor/psd/products/psd_device.mk by using a pa hooks file:

See previous commit for hammerhead.  This is much better than having to use device trees.
Use := and not += in product files.

Signed-off-by: Paul Beeler <pbeeler80@gmail.com>