ocxl: Make ocxl_remove() static

Fix sparse warning:

drivers/misc/ocxl/pci.c:44:6: warning:
 symbol 'ocxl_remove' was not declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>