usb: early/ehci-dbgp: make it explicitly non-modular

The Kconfig currently controlling compilation of this code is:

arch/x86/Kconfig.debug:config EARLY_PRINTK_DBGP
arch/x86/Kconfig.debug: bool "Early printk via EHCI debug port"

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

Lets remove the couple traces of modularity so that when reading the
driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>