Kconfig: Move config IDENT_STRING to Kconfig

Move the config IDENT_STRING to Kconfig and migrate all boards

[sivadur: Migrate zynq boards]
Signed-off-by: Siva Durga Prasad Paladugu <sivadur@xilinx.com>
[trini: Update configs, add some default to sunxi Kconfig]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/smdk5420_defconfig b/configs/smdk5420_defconfig
index ddf61a5..c1d8c45 100644
--- a/configs/smdk5420_defconfig
+++ b/configs/smdk5420_defconfig
@@ -2,6 +2,7 @@
 CONFIG_ARCH_EXYNOS=y
 CONFIG_ARCH_EXYNOS5=y
 CONFIG_TARGET_SMDK5420=y
+CONFIG_IDENT_STRING=" for SMDK5420"
 CONFIG_DEFAULT_DEVICE_TREE="exynos5420-smdk5420"
 CONFIG_FIT=y
 CONFIG_FIT_BEST_MATCH=y