imx: mx6ullevk: correct boot device macro

Correct boot device macro according to kconfig entry
in common/Kconfig

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Cc: Stefano Babic <sbabic@denx.de>

board/freescale/mx6ullevk/imximage.cfg

@@ -21,9 +21,9 @@ IMAGE_VERSION 2
  * spi/sd/nand/onenand, qspi/nor
  */
 
-#ifdef CONFIG_SYS_BOOT_QSPI
+#ifdef CONFIG_QSPI_BOOT
 BOOT_FROM	qspi
-#elif defined(CONFIG_SYS_BOOT_EIMNOR)
+#elif defined(CONFIG_NOR_BOOT)
 BOOT_FROM	nor
 #else
 BOOT_FROM	sd