platform/x86: asus-wmi: add SERIO_I8042 dependency

A recent bugfix added a call to i8042_install_filter but did
not add the dependency, leading to possible link errors:

drivers/platform/built-in.o: In function `asus_nb_wmi_quirks':
asus-nb-wmi.c:(.text+0x23af): undefined reference to `i8042_install_filter'

This adds a dependency on SERIO_I8042||SERIO_I8042=n to indicate
that we can build the driver when the i8042 driver is disabled,
but it cannot be built-in when that is a loadable module.

Fixes: b5643539 ("platform/x86: asus-wmi: Filter buggy scan codes on ASUS Q500A")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Darren Hart <dvhart@linux.intel.com>