tools: mkimage: Add support for i.MXRT FlexSPI Header

Modify imx8m Flex SPI Configuration Block to work with imxrt.
Add more Flex SPI configuration options to Kconfig.

Signed-off-by: Jesse Taube <Mr.Bossman075@gmail.com>
Tested-by:  Adam Ford <aford173@gmail.com> #imx8mn-beacon
diff --git a/include/imximage.h b/include/imximage.h
index c1ecc0b..a951699 100644
--- a/include/imximage.h
+++ b/include/imximage.h
@@ -210,33 +210,37 @@
 	uint8_t datasetup;
 	uint8_t coladdrwidth;
 	uint8_t devcfgenable;
-	uint8_t reserved_2[3];
+	uint8_t deviceModeType;
+	uint16_t waitTimeCfgCommands;
 	uint8_t devmodeseq[4];
-	uint8_t devmodearg[4];
+	uint32_t devmodearg;
 	uint8_t cmd_enable;
-	uint8_t reserved_3[3];
+	uint8_t configModeType[3];
 	uint8_t cmd_seq[16] ;
 	uint8_t cmd_arg[16];
-	uint8_t controllermisc[4];
+	uint32_t controllermisc;
 	uint8_t dev_type;
 	uint8_t sflash_pad;
 	uint8_t serial_clk;
-	uint8_t lut_custom ;
-	uint8_t reserved_4[8];
-	uint8_t sflashA1[4];
-	uint8_t sflashA2[4];
-	uint8_t sflashB1[4];
-	uint8_t sflashB2[4];
-	uint8_t cspadover[4];
-	uint8_t sclkpadover[4];
-	uint8_t datapadover[4];
-	uint8_t dqspadover[4];
-	uint8_t timeout[4];
-	uint8_t commandInt[4];
-	uint8_t datavalid[4];
-	uint8_t busyoffset[2];
-	uint8_t busybitpolarity[2];
+	uint8_t lut_custom;
+	uint8_t reserved_2[8];
+	uint32_t sflashA1;
+	uint32_t sflashA2;
+	uint32_t sflashB1;
+	uint32_t sflashB2;
+	uint32_t cspadover;
+	uint32_t sclkpadover;
+	uint32_t datapadover;
+	uint32_t dqspadover;
+	uint32_t timeout;
+	uint32_t commandInt;
+	uint16_t datavalid[2];
+	uint16_t busyoffset;
+	uint16_t busybitpolarity;
 	uint8_t lut[256];
+	uint8_t lutCustomSeq[48];
+	uint8_t reserved_3[16];
+
 } __attribute__((packed)) fspi_conf;
 
 typedef void (*set_dcd_val_t)(struct imx_header *imxhdr,