imx: add i.MX8MP EVK board

Add basic i.MX8MP EVK board support

U-Boot SPL 2020.01-rc4-00388-gb1bf40c0ae-dirty (Dec 30 2019 - 17:55:33 +0800)
power_pca9450b_init
DDRINFO: start DRAM init
DDRINFO:ddrphy calibration done
DDRINFO: ddrmix config done
Normal Boot
Failed to find clock node. Check device tree
WDT:   Not found!
Trying to boot from BOOTROM
image offset 0x8000, pagesize 0x200, ivt offset 0x0

U-Boot 2020.01-rc4-00388-gb1bf40c0ae-dirty (Dec 30 2019 - 17:55:33 +0800)

CPU:   Freescale i.MX8MP rev1.0 at 1000 MHz
Reset cause: POR
Model: NXP i.MX8MPlus EVK board
DRAM:  6 GiB
MMC:   FSL_SDHC: 1, FSL_SDHC: 2
Loading Environment from MMC... OK
In:    serial
Out:   serial
Err:   serial
Net:   No ethernet found.
Hit any key to stop autoboot:  0
u-boot=> mmc list
FSL_SDHC: 1 (SD)
FSL_SDHC: 2

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 251feb2..72affb1 100644
--- a/arch/arm/mach-imx/imx8m/Kconfig
+++ b/arch/arm/mach-imx/imx8m/Kconfig
@@ -44,10 +44,17 @@
 	select SUPPORT_SPL
 	select IMX8M_DDR4
 
+config TARGET_IMX8MP_EVK
+	bool "imx8mp LPDDR4 EVK board"
+	select IMX8MP
+	select SUPPORT_SPL
+	select IMX8M_LPDDR4
+
 endchoice
 
 source "board/freescale/imx8mq_evk/Kconfig"
 source "board/freescale/imx8mm_evk/Kconfig"
 source "board/freescale/imx8mn_evk/Kconfig"
+source "board/freescale/imx8mp_evk/Kconfig"
 
 endif