MAINTAINERS: Add entry for Socfpga DWMAC ethernet glue driver

MAINTAINERS: Add entry for Socfpga DWMAC ethernet glue driver

Socfpga's DWMAC glue comes in a variety of flavours with multiple
options when it comes to physical interfaces, making it not so easy to
test. Having access to a Cyclone5 with RGMII as well as Lynx PCS
variants, add myself as a maintainer to help with reviews and testing.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250416125453.306029-1-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>