warp7: Switch to DM Serial

This commit switches to DM SERIAL for warp7 and warp7_bl33 defconfigs.

Signed-off-by: Pierre-Jean Texier <pjtexier@koncepto.io>
Signed-off-by: Joris Offouga <offougajoris@gmail.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/configs/warp7_bl33_defconfig b/configs/warp7_bl33_defconfig
index 6eaf152..d34f76b 100644
--- a/configs/warp7_bl33_defconfig
+++ b/configs/warp7_bl33_defconfig
@@ -38,6 +38,8 @@
 CONFIG_DM_REGULATOR_PFUZE100=y
 CONFIG_DM_REGULATOR_FIXED=y
 CONFIG_DM_REGULATOR_GPIO=y
+CONFIG_SPECIFY_CONSOLE_INDEX=y
+CONFIG_DM_SERIAL=y
 CONFIG_USB=y
 CONFIG_USB_EHCI_HCD=y
 CONFIG_MXC_USB_OTG_HACTIVE=y