drm/nouveau/acpi: allow non-optimus setups to load vbios from acpi

There appear to be a crop of new hardware where the vbios is not
available from PROM/PRAMIN, but there is a valid _ROM method in ACPI.
The data read from PCIROM almost invariably contains invalid
instructions (still has the x86 opcodes), which makes this a low-risk
way to try to obtain a valid vbios image.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=76475
Signed-off-by: Ilia Mirkin <imirkin@alum.mit.edu>
Cc: <stable@vger.kernel.org> # v2.6.35+
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nouveau_acpi.c

@@ -389,9 +389,6 @@ bool nouveau_acpi_rom_supported(struct pci_dev *pdev)
 	acpi_status status;
 	acpi_handle dhandle, rom_handle;
 
-	if (!nouveau_dsm_priv.dsm_detected && !nouveau_dsm_priv.optimus_detected)
-		return false;
-
 	dhandle = ACPI_HANDLE(&pdev->dev);
 	if (!dhandle)
 		return false;