This fixes:
drivers/net/phy/b53/b53_priv.h:325:2: error: enumeration value '<board>' not handled in switch [-Werror=switch]
errors.
Fixes: 0de2213eeade7 ("kernel: b53: look for NVRAM's "robo_reset" entry on every platform")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>