MAINTAINERS: Add maintainer for MIPS Baikal-T1 platform code

Add myself as a maintainer of the MIPS Baikal-T1 platform-specific
drivers. The arch-code hasn't been submitted yet, but will be soon enough.
Until then it's better to have the already available drivers marked as
maintained.
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MAINTAINERS

@@ -14667,6 +14667,17 @@ F:	arch/mips/
 F:	drivers/platform/mips/
 F:	include/dt-bindings/mips/
 
+MIPS BAIKAL-T1 PLATFORM
+M:	Serge Semin <fancer.lancer@gmail.com>
+L:	linux-mips@vger.kernel.org
+S:	Supported
+F:	Documentation/devicetree/bindings/bus/baikal,bt1-*.yaml
+F:	Documentation/devicetree/bindings/clock/baikal,bt1-*.yaml
+F:	drivers/bus/bt1-*.c
+F:	drivers/clk/baikal-t1/
+F:	drivers/memory/bt1-l2-ctl.c
+F:	drivers/mtd/maps/physmap-bt1-rom.[ch]
+
 MIPS BOSTON DEVELOPMENT BOARD
 M:	Paul Burton <paulburton@kernel.org>
 L:	linux-mips@vger.kernel.org