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/gplugd_defconfig b/configs/gplugd_defconfig
index 6e14154..1a8ce9a 100644
--- a/configs/gplugd_defconfig
+++ b/configs/gplugd_defconfig
@@ -1,5 +1,6 @@
 CONFIG_ARM=y
 CONFIG_TARGET_GPLUGD=y
+CONFIG_IDENT_STRING="\nMarvell-gplugD"
 CONFIG_BOOTDELAY=3
 # CONFIG_CMD_IMLS is not set
 CONFIG_CMD_ASKENV=y