keystone2: use CONFIG_SOC_KEYSTONE in common places

Use CONFIG_SOC_KEYSTONE in common places instead of defining
a lot of "if def .. || if def " for different Keystone2 SoC types.

Acked-by: Murali Karicheri <m-karicheri2@ti.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>
diff --git a/common/image-fdt.c b/common/image-fdt.c
index 9fc7481..7795b80 100644
--- a/common/image-fdt.c
+++ b/common/image-fdt.c
@@ -492,7 +492,7 @@
 	if (!ft_verify_fdt(blob))
 		return -1;
 
-#ifdef CONFIG_SOC_K2HK
+#if defined(CONFIG_SOC_KEYSTONE)
 	if (IMAGE_OF_BOARD_SETUP)
 		ft_board_setup_ex(blob, gd->bd);
 #endif