[COMMANDS] Add host cpu info command

Add host cpu info command to display more information
of CPU from architecture specific code. host info dumps
the basic information.

The patch which will implement arch specific function for
x86 will follow.

Signed-off-by: Himanshu Chauhan <hschauhan@nulltrace.org>
Signed-off-by: Anup Patel <anup@brainfault.org>