global: Migrate CONFIG_TEGRA_BOARD_STRING to CFG

Perform a simple rename of CONFIG_TEGRA_BOARD_STRING to CFG_TEGRA_BOARD_STRING

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/arm/mach-tegra/board2.c b/arch/arm/mach-tegra/board2.c
index 54bbd8a..c7a45f4 100644
--- a/arch/arm/mach-tegra/board2.c
+++ b/arch/arm/mach-tegra/board2.c
@@ -89,7 +89,7 @@
 {
 	int board_id = tegra_board_id();
 
-	printf("Board: %s", CONFIG_TEGRA_BOARD_STRING);
+	printf("Board: %s", CFG_TEGRA_BOARD_STRING);
 	if (board_id != -1)
 		printf(", ID: %d\n", board_id);
 	printf("\n");