Move CONFIG_KVM related definitions to kvm_i386.h

pc.h and sysemu/kvm.h are also included from common code (where
CONFIG_KVM is not available), so the #defines that depend on CONFIG_KVM
should not be declared here to avoid that anybody is using them in a
wrong way. Since we're also going to poison CONFIG_KVM for common code,
let's move them to kvm_i386.h instead. Most of the dummy definitions
from sysemu/kvm.h are also unused since the code that uses them is
only compiled for CONFIG_KVM (e.g. target/i386/kvm.c), so the unused
defines are also simply dropped here instead of being moved.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1498454578-18709-3-git-send-email-thuth@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
