davinci: remove macro CONFIG_DISPLAY_CPUINFO

remove the macro CONFIG_DISPLAY_CPUINFO as it is no longer
required. This is because clock info will be printed as part
'bdinfo' command and also remove support print_cpuinfo() as it will
no longer be called.

Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
Cc: Tom Rini <trini@ti.com>