spd: opteed: enable NS_TIMER_SWITCH
spd: opteed: enable NS_TIMER_SWITCH

Enable dispatcher to save/restore unbanked timer registers. So that
both secure (OP-TEE) and non-secure (Linux) worlds can have independent
access control over timer registers.

Signed-off-by: Sumit Garg <0904b466d9452daa97eb086f40b9aaa7e498e972@linaro.org>
Change-Id: I4d58d5ff8298587ed478c8433fcbc3aef538d668

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware