KVM: arm64: selftests: Test ESR propagation for vSError injection

Ensure that vSErrors taken in the guest have an appropriate ESR_ELx
value for the expected exception. Additionally, switch the EASE test to
install the SEA handler at the SError offset, as the ESR is still
expected to match an SEA in that case.

Link: https://lore.kernel.org/r/20250708230632.1954240-3-oliver.upton@linux.dev


Signed-off-by: Oliver Upton <oliver.upton@linux.dev>