MAINTAINERS: Add lowrisc files to RISC-V

Change-Id: I8e9ff5821e15cd9a5966927a8cd8bd95f7021d58
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-on: https://review.coreboot.org/17402
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 5078bb0..015dbbf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -124,8 +124,10 @@
 M:	Jonathan Neuschäfer <j.neuschaefer@gmx.net>
 S:	Maintained
 F:	src/arch/riscv/
+F:	src/soc/lowrisc
 F:	src/soc/ucb/
 F:	src/mainboard/emulation/*-riscv/
+F:	src/mainboard/lowrisc
 
 POWER8 ARCHITECTURE
 M:	Ronald Minnich <rminnich@gmail.com>