bmpblk: Remove nocturne recovery screen SD Card option

Nocturne's recovery screen still shows SD Card as an option
for recovery, but nocturne doesn't have SD Card support.

Use 7-bit color instead of 4.

BUG=b:116172502
BRANCH=firmware-nocturne-10984.B
TEST=Build and flash image, boot into recovery mode, verify
SD Card is no longer an option.

Change-Id: Ifb49cf46418c9048a59b7b2736ab674f9238f7b1
Signed-off-by: Nick Vaccaro <nvaccaro@google.com>
diff --git a/images/boards.yaml b/images/boards.yaml
index b50c139..fc79a4a 100644
--- a/images/boards.yaml
+++ b/images/boards.yaml
@@ -306,8 +306,8 @@
 nocturne:
   # 3000x2000, boots recovery image on USB ports.
   screen:   [3000, 2000]
+  sdcard:   False
   hi_res:   [en]
-  text_colors:  4
 
 rammus:
   # 1920x1080, boots recovery image on USB ports.