build: convert crash_debug to Kconfig

build: convert crash_debug to Kconfig

Convert the crash_debug option to Kconfig as CONFIG_CRASH_DEBUG. This
was previously togglable on the command line so this adds a message for
users enabling it from the command line to tell them to enable it from
make menuconfig.

Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>