layout: Move generic layout functions into `layout.c`

Change-Id: If1edde70fc51e88e6e1c560d79a0d51941b9627c
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/33514
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
diff --git a/Doxyfile b/Doxyfile
index d2a7695..6906cc8 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -782,7 +782,8 @@
 
 INPUT                  = libflashrom.c \
                          libflashrom.h \
-                         flashrom.c
+                         flashrom.c \
+                         layout.c \
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses