KVM: arm64: Expose self-hosted debug regs as RAZ/WI for protected guests

KVM: arm64: Expose self-hosted debug regs as RAZ/WI for protected guests

Debug and trace are not currently supported for protected guests, so
trap accesses to the related registers and emulate them as RAZ/WI for
now. Although this isn't strictly compatible with the architecture, it's
sufficient for Linux guests and means that debug support can be added
later on.

Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-7-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>