TESTING-ONLY: KVM: arm64: Allow user-space to claim guest SMC-CC ranges for SDEI

Instead of supporting SDEI in KVM, and providing a new API to
control and configure the in-kernel support, allow user-space to
request particular SMC-CC ranges from guest HVC calls to be handled
by user-space.

This requires two KVM capabilities, KVM_CAP_ARM_SDEI_1_0 advertises
that KVM knows how match SDEI SMC-CC calls from a guest. To pass these
calls to user-space requires this cap to be enabled using
KVM_CAP_ENABLE_CAP_VM.

Calls are passed with exit_reason = KVM_EXIT_HYPERCALL, the kvm_run
structure has copies of the first 6 registers and the guest pstate.

...

A much better way of doing this is to let user-space claim everything
HCR_EL2.TSC or HVC traps, this covers immediates and avoids future work
for the kernel to match the SMC-CC range.

This would no longer depend on SDEI, so can be done separatly. This patch
is now just-for-testing.

While I'm in here, remove KVM_CAP_ARM_SET_DEVICE_ADDR's extra entry
for r=1;break?

Not-at-all-signed-off