MAINTAINERS: Add some missing directories or files

In a few cases we have MAINTAINERS entries that are missing obvious
paths or files. Typically this means a board directory that did not list
itself, but in a few cases we have a Kconfig file or similar.

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/devboards/dbm-soc1/MAINTAINERS b/board/devboards/dbm-soc1/MAINTAINERS
index 625f2c8..577eba5 100644
--- a/board/devboards/dbm-soc1/MAINTAINERS
+++ b/board/devboards/dbm-soc1/MAINTAINERS
@@ -1,5 +1,6 @@
 Devboards.de DBM-SoC1 BOARD
 M:	Marek Vasut <marex@denx.de>
 S:	Maintained
+F:	board/devboards/dbm-soc1/
 F:	include/configs/socfpga_dbm_soc1.h
 F:	configs/socfpga_dbm_soc1_defconfig