Split CONFIG_CC_OPTIMIZE_FOR_SIZE into two configs

This adds a separate CONFIG_CC_OPTIMIZE_FOR_SPEED option in a choice,
in preparation for adding another optimization option. Also convert SH's
makefile to use this new option.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/Kconfig b/Kconfig
index 9dd9ec7..8159c59 100644
--- a/Kconfig
+++ b/Kconfig
@@ -72,15 +72,26 @@
 	int
 	default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
 
+choice
+	prompt "Optimization level"
+	default CC_OPTIMIZE_FOR_SIZE
+
 config CC_OPTIMIZE_FOR_SIZE
 	bool "Optimize for size"
-	default y
 	help
-	  Enabling this option will pass "-Os" instead of "-O2" to gcc
-	  resulting in a smaller U-Boot image.
+	  Enabling this option will pass "-Os" to gcc, resulting in a smaller
+	  U-Boot image.
 
 	  This option is enabled by default for U-Boot.
 
+config CC_OPTIMIZE_FOR_SPEED
+	bool "Optimize for speed"
+	help
+	  Enabling this option will pass "-O2" to gcc, resulting in a faster
+	  U-Boot image.
+
+endchoice
+
 config OPTIMIZE_INLINING
 	bool "Allow compiler to uninline functions marked 'inline' in full U-Boot"
 	help