esp: fix migration version check in esp_is_version_5()

esp: fix migration version check in esp_is_version_5()

Commit 4e78f3bf35 "esp: defer command completion interrupt on incoming data
transfers" added a version check for use with VMSTATE_*_TEST macros to allow
migration from older QEMU versions. Unfortunately the version check fails to
work in its current form since if the VMStateDescription version_id is
incremented, the test returns false and so the fields are not included in the
outgoing migration stream.

Change the version check to use >= rather == to ensure that migration works
correctly when the ESPState VMStateDescription has version_id > 5.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Fixes: 4e78f3bf35 ("esp: defer command completion interrupt on incoming data transfers")
Message-Id: <20210613102614.5438-1-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>