gpu: nvgpu: add MISRA-compliant string ops

Add nvgpu_memcpy/nvgpu_memcmp which are MISRA-compliant versions
(Rule 21.15) of memcpy/memcmp.

Also convert some clk/gr calls over to use the new routines;
all of the remaining calls will be converted in subsequent patches.

JIRA NVGPU-849

Change-Id: Ib3a602cd08886764ba9a50285462a8b07bfb18ba
Signed-off-by: Scott Long <scottl@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1919470
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

drivers/gpu/nvgpu/common/string.c

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2018, 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/>.
+ */
+
+#include <nvgpu/string.h>
+
+void
+nvgpu_memcpy(u8 *destb, const u8 *srcb, size_t n)
+{
+	(void) memcpy(destb, srcb, n);
+}
+
+int
+nvgpu_memcmp(const u8 *b1, const u8 *b2, size_t n)
+{
+	return memcmp(b1, b2, n);
+}