configs: drop CONFIG_MMCROOT

CONFIG_MMCROOT is only used to set mmcroot, no need a dedicated macro.

Script as below
"
 for i in `ls include/configs/*.h`
 do
 mmcroot=`sed -n '/define.*MMCROOT/ p' $i  | awk -F\" '{ print $2;}'`

 if [ ! -n "$mmcroot" ]; then
 	continue
 fi

 sed -i '/define.*MMCROOT/ d' $i
 sed -i 's,\" CONFIG_MMCROOT \",'$mmcroot',g' $i

 done
"

Reviewed-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/include/configs/pico-imx8mq.h b/include/configs/pico-imx8mq.h
index 495fddf..9584527 100644
--- a/include/configs/pico-imx8mq.h
+++ b/include/configs/pico-imx8mq.h
@@ -46,7 +46,7 @@
 	"initrd_high=0xffffffffffffffff\0"				\
 	"mmcdev=" __stringify(CONFIG_SYS_MMC_ENV_DEV) "\0"		\
 	"mmcpart=1\0"	\
-	"mmcroot=" CONFIG_MMCROOT " rootwait rw\0"			\
+	"mmcroot=/dev/mmcblk1p2 rootwait rw\0"			\
 	"mmcautodetect=yes\0"						\
 	"mmcargs=setenv bootargs console=${console} root=${mmcroot}\0 "	\
 	"loadbootscript="						\
@@ -80,7 +80,6 @@
 #define CONFIG_SYS_INIT_SP_ADDR		\
 	(CONFIG_SYS_INIT_RAM_ADDR + CONFIG_SYS_INIT_SP_OFFSET)
 
-#define CONFIG_MMCROOT			"/dev/mmcblk1p2"	/* USDHC2 */
 
 #define CONFIG_SYS_SDRAM_BASE		0x40000000
 #define PHYS_SDRAM			0x40000000