I think the clock speed may be given. The Samsung Galaxy S II uses a dual core Arm-Cortex A9 clocked at 1.2 GHz, called Exynos. Granted the Vita uses the A9 as well but quad core (1 core locked), could it be possible it will run at 1.2Ghz as well?
However the Exynos doesn't use PowerVR for GPU, unlike the Vita and their own previous, Hummingbird.
Given, All CPU's are being manufactured by Samsung.
EDIT: Ahh nvm, i got tangled with Tegra. Seems like Vita may have a 1GHz A9 with the 200MHz Power VR.
EDIT2: Seeing upcoming Tegra 2 processors, Sony should have gone with Tegra 2. Though batery life would have been a problem.
e=mc^2
Gaming on: PS4 Pro, Switch, SNES Mini, Wii U, PC (i5-7400, GTX 1060)