puzzles: only build manual for color targets

'SUBDIRS' file has puzzles inside a 'HAVE_LCD_COLOR' block. I found this
issue because sgt-puzzles was in the Clip+ docs while they were not
installed on the target.

Change-Id: I8ddf43fa75c8429d2f1a99f13689a5442913748e

2 files changed, 2 insertions, 1 deletions

diff --git a/docs/CREDITS b/docs/CREDITS
index b1a9675f8f..d47f12e625 100644
--- a/docs/CREDITS
+++ b/docs/CREDITS
@@ -700,6 +700,7 @@ Yuxuan Shui
 James Buren
 Issa Beganović
 Georg Gadinger
+Wolfram Sang
 
 The libmad team
 The wavpack team
diff --git a/manual/plugins/main.tex b/manual/plugins/main.tex
index 786b83355d..3348b1fce5 100644
--- a/manual/plugins/main.tex
+++ b/manual/plugins/main.tex
@@ -82,7 +82,7 @@ text files%
 
 \input{plugins/rockblox1d.tex}
 
-\input{plugins/sgt-puzzles.tex}
+\opt{lcd_color}{\input{plugins/sgt-puzzles.tex}}
 
 \input{plugins/sliding.tex}