drivers/tty: make hvc_console.c explicitly non-modular

The Kconfig currently controlling compilation of this code is:

drivers/tty/hvc/Kconfig:config HVC_DRIVER
drivers/tty/hvc/Kconfig:        bool

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only, even
though someone bothered to comment that the code was not used.

Unlike other changes, this driver binds in w/o using module_init,
so we dont have init ordering concerns with this commit.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>