drm/bochs: Fix the ID mismatch error

drm/bochs: Fix the ID mismatch error

When running RISC-V QEMU with the Bochs device attached via PCIe the
probe of the Bochs device fails with:
    [drm:bochs_hw_init] *ERROR* ID mismatch

This was introduced by this commit:
    7780eb9ce8 bochs: convert to drm_dev_register

To fix the error we ensure that pci_enable_device() is called before
bochs_load().

Fixes: 7780eb9ce80f ("bochs: convert to drm_dev_register")
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reported-by: David Abdurachmanov <david.abdurachmanov@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20190221003231.31625-1-alistair.francis@wdc.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>