bootconfig: Change message if no bootconfig with CONFIG_BOOT_CONFIG_FORCE=y

Change no bootconfig data error message if user do not specify 'bootconfig'
option but CONFIG_BOOT_CONFIG_FORCE=y.
With CONFIG_BOOT_CONFIG_FORCE=y, the kernel proceeds bootconfig check even
if user does not specify 'bootconfig' option. So the current error message
is confusing. Let's show just an information message to notice skipping
the bootconfig in that case.

Link: https://lore.kernel.org/all/167754610254.318944.16848412476667893329.stgit@devnote2/

Fixes: b743852c

 ("Allow forcing unconditional bootconfig processing")
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/all/CAMuHMdV9jJvE2y8gY5V_CxidUikCf5515QMZHzTA3rRGEOj6=w@mail.gmail.com/
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>