net: mdio: select REGMAP_MMIO instead of depending on it

net: mdio: select REGMAP_MMIO instead of depending on it

REGMAP_MMIO is a hidden (non-user-visible) tristate symbol. Using
depends on it is incorrect because there is no way for the user to
enable it directly. Change to select, which is the convention used
by every other driver in the tree that needs REGMAP_MMIO.

Fixes: 8057cbb8335c ("net: mdio: mscc-miim: Add depend of REGMAP_MMIO on MDIO_MSCC_MIIM")
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20260702032653.1580616-1-rosenp@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>