spl: display_options.o is required for SPI flash support in SPL

Signed-off-by: NChristian Riesch <christian.riesch@omicron.at>
Cc: Heiko Schocher <hs@denx.de>
Cc: Mike Frysinger <vapier@gentoo.org>

lib/Makefile

@@ -50,6 +50,8 @@ COBJS-$(CONFIG_SHA1) += sha1.o
 COBJS-$(CONFIG_SHA256) += sha256.o
 COBJS-y	+= strmhz.o
 COBJS-$(CONFIG_RBTREE)	+= rbtree.o
+else
+COBJS-$(CONFIG_SPL_SPI_FLASH_SUPPORT) += display_options.o
 endif
 
 COBJS-y += ctype.o