Convert CONFIG_CFB_CONSOLE_ANSI to Kconfig

This converts the following to Kconfig:
   CONFIG_CFB_CONSOLE_ANSI

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/nokia_rx51_defconfig b/configs/nokia_rx51_defconfig
index d4591c9..65c5d68 100644
--- a/configs/nokia_rx51_defconfig
+++ b/configs/nokia_rx51_defconfig
@@ -23,3 +23,4 @@
 CONFIG_CMD_EXT4=y
 CONFIG_CMD_FAT=y
 CONFIG_SYS_NS16550=y
+CONFIG_CFB_CONSOLE_ANSI=y