gpu: nvgpu: Debugfs for S_param

Changes:
1) Added nvgpu_s_param_init_debugfs for creating debugfs interface.
2) Command for S_param value:
   cat /sys/kernel/debug/gpu_pci/s_param
3) vfe_var_boardobj_grp_get_status is implemented.

Jira NVGPU-1736

Change-Id: Icbcf39e47777fe969ae2592b58a3103a21011a87
Signed-off-by: rmylavarapu <rmylavarapu@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1989334
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/os/linux/debug_s_param.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2019, 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 __DEBUG_S_PARAM_TU104_H
+#define __DEBUG_S_PARAM_TU104_H
+
+#include <nvgpu/gk20a.h>
+
+#ifdef CONFIG_DEBUG_FS
+int nvgpu_s_param_init_debugfs(struct gk20a *g);
+#else
+static inline int nvgpu_s_param_init_debugfs(struct gk20a *g)
+{
+	return 0;
+}
+#endif
+
+#endif