microblaze: Make the board configuration name user definable

Add a prompt for editing in menuconfig
Signed-off-by: NSai Pavan Boddu <saipava@xilinx.com>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>

board/xilinx/microblaze-generic/Kconfig

@@ -7,7 +7,12 @@ config SYS_VENDOR
 	default "xilinx"
 
 config SYS_CONFIG_NAME
+	string "Board configuration name"
 	default "microblaze-generic"
+	help
+	  This option contains information about board configuration name.
+	  Based on this option include/configs/<CONFIG_SYS_CONFIG_NAME>.h header
+	  will be used for board configuration.
 
 config XILINX_MICROBLAZE0_USE_MSR_INSTR
 	int "USE_MSR_INSTR range (0:1)"