firmware: qcom_scm-64: Add atomic version of qcom_scm_call

There are scnenarios where drivers are required to make a
scm call in atomic context, such as in one of the qcom's
arm-smmu-500 errata [1].

[1] ("https://source.codeaurora.org/quic/la/kernel/msm-4.9/


      tree/drivers/iommu/arm-smmu.c?h=msm-4.9#n4842")

Change-Id: I5b313e6629a7ea54055c2cd83d439f5f0d9069c1
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Andy Gross <agross@kernel.org>
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Patch-mainline: https://lore.kernel.org/patchwork/patch/1129992/


Signed-off-by: Elliot Berman <eberman@codeaurora.org>