mpu_wrappers_v2.c: fix cpp build warnings

fix cpp build warning due to missing braces around initialization of
subobject with xKernelObjectPool array

Fixes: MCUSDK-14291

Signed-off-by: Don Dominic <don.dominic@ti.com>

Author: dondmadappallil

portable/Common/mpu_wrappers_v2.c

@@ -250,7 +250,7 @@
 /**
  * @brief Kernel object pool.
  */
-    PRIVILEGED_DATA static KernelObject_t xKernelObjectPool[ configPROTECTED_KERNEL_OBJECT_POOL_SIZE ] = { 0 };
+    PRIVILEGED_DATA static KernelObject_t xKernelObjectPool[ configPROTECTED_KERNEL_OBJECT_POOL_SIZE ] = { { 0 } };
 /*-----------------------------------------------------------*/
 
     static int32_t MPU_GetFreeIndexInKernelObjectPool( void ) /* PRIVILEGED_FUNCTION */