s390/pci: Drop unneeded reference to CONFIG_DMI

The S/390 architecture doesn't support SMBIOS, so CONFIG_DMI will
never be defined there. So we can simply omit these preprocessing
directives and speed up the build a bit.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20240423162724.3966265a@endymion.delvare
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>