imx: imx8mn_ddr4_evk: Use CONFIG_TARGET_IMX8MN_DDR4_EVK for DDR4 EVK board

use CONFIG_TARGET_IMX8MN_DDR4_EVK for DDR4 EVK board, we will use
CONFIG_TARGET_IMX8MN_EVK for LPDDR4 EVK board.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/mach-imx/imx8m/Kconfig b/arch/arm/mach-imx/imx8m/Kconfig
index 8615dc3..bd2ab77 100644
--- a/arch/arm/mach-imx/imx8m/Kconfig
+++ b/arch/arm/mach-imx/imx8m/Kconfig
@@ -43,7 +43,7 @@
 	select SUPPORT_SPL
 	select IMX8M_LPDDR4
 
-config TARGET_IMX8MN_EVK
+config TARGET_IMX8MN_DDR4_EVK
 	bool "imx8mn DDR4 EVK board"
 	select IMX8MN
 	select SUPPORT_SPL
diff --git a/board/freescale/imx8mn_evk/Kconfig b/board/freescale/imx8mn_evk/Kconfig
index 38ac846..048fb7d 100644
--- a/board/freescale/imx8mn_evk/Kconfig
+++ b/board/freescale/imx8mn_evk/Kconfig
@@ -1,4 +1,4 @@
-if TARGET_IMX8MN_EVK
+if TARGET_IMX8MN_DDR4_EVK
 
 config SYS_BOARD
 	default "imx8mn_evk"
diff --git a/configs/imx8mn_ddr4_evk_defconfig b/configs/imx8mn_ddr4_evk_defconfig
index 41889c4..f7ea658 100644
--- a/configs/imx8mn_ddr4_evk_defconfig
+++ b/configs/imx8mn_ddr4_evk_defconfig
@@ -12,7 +12,7 @@
 CONFIG_SYS_I2C_MXC_I2C3=y
 CONFIG_DM_GPIO=y
 CONFIG_SPL_TEXT_BASE=0x912000
-CONFIG_TARGET_IMX8MN_EVK=y
+CONFIG_TARGET_IMX8MN_DDR4_EVK=y
 CONFIG_SPL_MMC_SUPPORT=y
 CONFIG_SPL_SERIAL_SUPPORT=y
 CONFIG_SPL_DRIVERS_MISC_SUPPORT=y