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>
1 file changed