drivers/hsi: include <module.h> for modular omap_ssi code

These files are built off of a tristate Kconfig option and also contain
modular function calls so they should explicitly include module.h to
avoid compile breakage during header shuffles done in the future.

We change the one header file wich gives us coverage on both files:
   drivers/hsi/controllers/omap_ssi.c
   drivers/hsi/controllers/omap_ssi_port.c

Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>