TARGET_MIMXRT1050: fix vector table redef from cmsis

We need a linker script as it was. As files update in the future, should be compatible
with newer CMSIS core.

Author: 0xc0170

targets/TARGET_NXP/TARGET_MCUXpresso_MCUS/TARGET_MIMXRT1050/drivers/fsl_flexspi_nor_boot.h

@@ -10,6 +10,7 @@
 
 #include <stdint.h>
 #include "device.h"
+#undef __VECTOR_TABLE
 
 /*! @name Driver version */
 /*@{*/