mtd: update description of MTD_BCM47XXSFLASH symbol

For years now we support writing to BCMA SoC serial flash, so don't
describe this driver as providing read-only support anymore.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
1 file changed