KVM: arm64: Set SCTLR_EL2.DSSBS if SSBD is forcefully disabled and !vhe

KVM: arm64: Set SCTLR_EL2.DSSBS if SSBD is forcefully disabled and !vhe

BugLink: https://bugs.launchpad.net/bugs/1851876
[ Upstream commit 7c36447ae5a090729e7b129f24705bb231a07e0b ]

When running without VHE, it is necessary to set SCTLR_EL2.DSSBS if SSBD
has been forcefully disabled on the kernel command-line.

Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>