KVM: x86: Bury emulator read/write ops in emulator_{read,write}_emulated()

KVM: x86: Bury emulator read/write ops in emulator_{read,write}_emulated()

Now that SEV-ES invokes vcpu_mmio_{read,write}() directly, bury the
read vs. write emulator ops in the dedicated emulator callbacks so that
they are colocated with their usage, and to make it harder for
non-emulator code to use hooks that are intended for the emulator.

Opportunistically rename the structures to get rid of the long-standing
"emultor" typo.

No functional change intended.

Tested-by: Tom Lendacky <thomas.lendacky@gmail.com>
Tested-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Link: https://patch.msgid.link/20260225012049.920665-11-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>