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/sheevaplug_defconfig b/configs/sheevaplug_defconfig
index dbafcf2..e4c846f 100644
--- a/configs/sheevaplug_defconfig
+++ b/configs/sheevaplug_defconfig
@@ -1,6 +1,7 @@
 CONFIG_ARM=y
 CONFIG_KIRKWOOD=y
 CONFIG_TARGET_SHEEVAPLUG=y
+CONFIG_IDENT_STRING="\nMarvell-Sheevaplug"
 CONFIG_BOOTDELAY=3
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_BOOTZ=y