gpu: nvgpu: linux: add virtual function support

vf probe is called by pci general probe when platform data indicates
it's a virtual device.
vf_linux covers PCIE specific initialization, then call common vgpu
probe.

Jira GVSCI-15779

Change-Id: I47ce1c4807b23363a9062ff0cbc8e08b9c6cdc97
Signed-off-by: Richard Zhao <rizhao@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/c/linux-nvgpu/+/2884177
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/os/linux/vgpu/vf_linux.h

@@ -0,0 +1,33 @@
+/*
+  * Copyright (c) 2023, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef NVGPU_VF_LINUX_H
+#define NVGPU_VF_LINUX_H
+
+struct pci_dev;
+struct gk20a_platform;
+
+#ifdef CONFIG_NVGPU_GR_VIRTUALIZATION
+int vf_probe(struct pci_dev *pdev, struct gk20a_platform *platform);
+#else
+static inline int vf_probe(struct pci_dev *pdev,
+		struct gk20a_platform *platform)
+{
+	return -ENOSYS;
+}
+#endif
+
+#endif