drivers/acpi: make apei/ghes.c more explicitly non-modular

The Kconfig currently controlling compilation of this code is:

config ACPI_APEI_GHES
      bool "APEI Generic Hardware Error Source"

...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.

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

We replace module.h with moduleparam.h as we are keeping the
pre-existing module_param that the file has, as currently that is
the easiest way to maintain compatibility with the existing boot
arg use cases.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>