nxp: adding the smmu driver

NXP SMMU driver API for NXP SoC.
- Currently it supports by-passing SMMU, called only when NXP CAAM
is enabled.
- (TBD) AMQ based SMMU access control: Access Management Qualifiers (AMQ)
  advertised by a bus master for a given transaction.
Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Change-Id: I23a12928ddedb1a2cf4b396606e35c67e016e331

include/drivers/nxp/smmu/nxp_smmu.h

+/*
+ * Copyright 2018-2020 NXP
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#ifndef NXP_SMMU_H
+#define NXP_SMMU_H
+
+#define SMMU_SCR0		(0x0)
+#define SMMU_NSCR0		(0x400)
+
+#define SCR0_CLIENTPD_MASK	0x00000001
+#define SCR0_USFCFG_MASK	0x00000400
+
+static inline void bypass_smmu(uintptr_t smmu_base_addr)
+{
+	uint32_t val;
+
+	val = (mmio_read_32(smmu_base_addr + SMMU_SCR0) | SCR0_CLIENTPD_MASK) &
+		~(SCR0_USFCFG_MASK);
+	mmio_write_32((smmu_base_addr + SMMU_SCR0), val);
+
+	val = (mmio_read_32(smmu_base_addr + SMMU_NSCR0) | SCR0_CLIENTPD_MASK) &
+		~(SCR0_USFCFG_MASK);
+	mmio_write_32((smmu_base_addr + SMMU_NSCR0), val);
+}
+
+#endif