arm64: xilinx: Enable generic of_board_dtb

Modify the configuration naming to be generic to xilinx rather than
specific to Versal. The offset value is different for Zynq and ZynqMP
to avoid overlapping with FSBL.

Signed-off-by: Ibai Erkiaga <ibai.erkiaga-elorza@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/board/xilinx/Kconfig b/board/xilinx/Kconfig
index 4f29033..cb272ea 100644
--- a/board/xilinx/Kconfig
+++ b/board/xilinx/Kconfig
@@ -40,9 +40,10 @@
 
 endif
 
-config VERSAL_OF_BOARD_DTB_ADDR
+config XILINX_OF_BOARD_DTB_ADDR
 	hex
-	default 0x1000
+	default 0x1000 if ARCH_VERSAL
+	default 0x100000 if ARCH_ZYNQ || ARCH_ZYNQMP
 	depends on OF_BOARD
 	help
 	  Offset in the memory where the board configuration DTB is placed.