ts-kernel-build: Disable CONFIG_ARCH_QCOM in Xen Project CI

ts-kernel-build: Disable CONFIG_ARCH_QCOM in Xen Project CI

  drivers/firmware/qcom_scm.c:469:47: error: passing argument 3 of `dma_alloc_coherent' from incompatible pointer type [-Werror=incompatible-pointer-types]

This is fixed by

  firmware: qcom_scm: Use proper types for dma mappings

but this is not present in all relevant stable branches.

We currently have no Qualcomm hardware in the Xen Project test lab so
we do not need this enabled.

CC: Stefano Stabellini <sstabellini@kernel.org>
CC: linux-arm-msm@vger.kernel.org
CC: linux-kernel@vger.kernel.org
CC: Stephen Boyd <swboyd@chromium.org>
CC: Andy Gross <agross@kernel.org>
CC: Bjorn Andersson <bjorn.andersson@linaro.org>
CC: Avaneesh Kumar Dwivedi <akdwived@codeaurora.org>
Acked-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>