i.MX7ULP: Add CONFIG_MX7ULP to kconfig

Since many drivers need this CONFIG_MX7ULP to distiguish the settings
for i.MX7ULP only. Add this entry to cpu's kconfig.

Signed-off-by: Ye Li <ye.li@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
1 file changed