staging: kpc2000: remove fileops.c file.

The fileops.c file does not need to be stand-alone, so move it into the
core.c file.  This lets us make some functions static, reducing the
global namespace of the driver.

Cc: Matt Sickler <Matt.Sickler@daktronics.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>