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/terasic/sockit/MAINTAINERS b/board/terasic/sockit/MAINTAINERS
index 792f184..e301751 100644
--- a/board/terasic/sockit/MAINTAINERS
+++ b/board/terasic/sockit/MAINTAINERS
@@ -1,5 +1,6 @@
 SOCKIT BOARD
 M:	Marek Vasut <marex@denx.de>
 S:	Maintained
+F:	board/terasic/sockit/
 F:	include/configs/socfpga_sockit.h
 F:	configs/socfpga_sockit_defconfig