cfb_console: Add support for some ANSI terminal escape codes

Add optional support for some ANSI escape sequences to the
cfb_console driver. Define CONFIG_CFB_CONSOLE_ANSI to enable
cursor moving, color reverting and clearing the cfb console
via ANSI escape codes.

Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Anatolij Gustschin <agust@denx.de>