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 <[e-mail]>
Reported-by: David Abdurachmanov <[e-mail]>
Link: http://patchwork.freedesktop.org/patch/msgid/[e-mail]
Signed-off-by: Gerd Hoffmann <[e-mail]>
Signed-off-by: Dave Airlie <[e-mail]>

drivers/gpu/drm/bochs/bochs_drv.c

···
 	if (IS_ERR(dev))
 		return PTR_ERR(dev);
 
+	ret = pci_enable_device(pdev);
+	if (ret)
+		goto err_free_dev;
+
 	dev->pdev = pdev;
 	pci_set_drvdata(pdev, dev);