configs: drop CONFIG_MMCROOT

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>