arm: rmobile: lager: Enable optimization of thumb

This adds CONFIG_SYS_THUMB_BUILD to config, in order to enable optimization
of thumb.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>

include/configs/lager.h

@@ -36,6 +36,7 @@
 #define CONFIG_CMD_SF
 #define CONFIG_CMD_SPI
 #define CONFIG_SYS_TEXT_BASE	0xE8080000
+#define CONFIG_SYS_THUMB_BUILD
 
 #define	CONFIG_CMDLINE_TAG
 #define	CONFIG_SETUP_MEMORY_TAGS