ArmPkg/OpteeLib: Add APIs to communicate with OP-TEE

ArmPkg/OpteeLib: Add APIs to communicate with OP-TEE

Add following APIs to communicate with OP-TEE pseudo/early TAs:
1. OpteeInit
2. OpteeOpenSession
3. OpteeCloseSession
4. OpteeInvokeFunc

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>