Blackfin: enable -O2 in lib_generic/ for ADI/Bluetechnix boards

Building the compression code in lib_generic/ with -O2 rather than -Os
gives a nice speed boost without too much code size increase.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/board/bf548-ezkit/config.mk b/board/bf548-ezkit/config.mk
index 95ab6b3..42ff946 100644
--- a/board/bf548-ezkit/config.mk
+++ b/board/bf548-ezkit/config.mk
@@ -26,6 +26,9 @@
 # This is not actually used for Blackfin boards so do not change it
 #TEXT_BASE = do-not-use-me
 
+CFLAGS_lib_generic += -O2
+CFLAGS_lzma += -O2
+
 # Set some default LDR flags based on boot mode.
 LDR_FLAGS-BFIN_BOOT_PARA       := --dma 6
 LDR_FLAGS-BFIN_BOOT_FIFO       := --dma 1