powervr: add powervr virtual package

Signed-off-by: Spenser Gilliland <spenser@gillilanding.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Sundareson, Prabindh <prabu@ti.com>
Cc: Peter Korsgaard <jacmet@uclibc.org>
Cc: Sinan Akpolat <sinan@linkas.com.tr>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>