[LTD fromlist] arm: soc: nxp k6x: MPU: add Bus Master 3 User Mode access bits

Ethernet on K64F is connected via Logical Bus Master 3.
Section 19.3.8 of K64F reference manual establishes bits 20-18
(M3UM) on page 427 as "Bus Master 3 User Mode Access Control".

To fix RW via Bus Master 3 when MPU is enabled, we need to add
these bits to the MPU region descriptors.

This fixes ETH0 on K64F when MPU is enabled.

Fix recommended by Maureen Helm <[email protected]>

Signed-off-by: Michael Scott <[email protected]>
Signed-off-by: Marti Bolivar <[email protected]>

Author: Michael Scott

include/arch/arm/cortex_m/mpu/nxp_mpu.h

@@ -14,10 +14,12 @@
 #define NXP_MPU_REGION_NUMBER 12
 
 /* Read Attribute */
-#define MPU_REGION_READ  ((1 << 2) | (1 << 8) | (1 << 14))
+#define MPU_REGION_READ  ((1 << 2) | (1 << 8) | (1 << 14) | \
+			  (1 << 18) | (1 << 19) | (1 << 20))
 
 /* Write Attribute */
-#define MPU_REGION_WRITE ((1 << 1) | (1 << 7) | (1 << 13))
+#define MPU_REGION_WRITE ((1 << 1) | (1 << 7) | (1 << 13) | \
+			  (1 << 18) | (1 << 19) | (1 << 20))
 
 /* Execute Attribute */
 #define MPU_REGION_EXEC  ((1 << 0) | (1 << 6) | (1 << 12))