Commit f724a583dc updated the nand-rb4xx driver to the 5.10 testing
kernel, but forgot to add the new kernel config symbol it introduces to
the 5.10 config.
Fixes: f724a583dc ("ath79: mikrotik: update nand-rb4xx driver")
Reported-by: Russell Senior <russell@personaltelco.net>
Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>
f4473baf6e