__delay is exported by most architectures, and may be used in modules.
Since it is not exported for s390, s390:allmodconfig currently fails
to build with
Fixes: a6d678645210 ("net: mdio-octeon: Modify driver to work on both
ThunderX and Octeon") Cc: Radha Mohan Chintakuntla <rchintakuntla@cavium.com> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>