arm64: zynqmp: allow overriding board name

There is no need to use zynqmp name as SYS_BOARD for all boards.
The patch is adding an option to change it.

Signed-off-by: Liam Beguin <liambeguin@gmail.com>
Link: https://lore.kernel.org/r/20211020152518.3511912-1-liambeguin@gmail.com
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/mach-zynqmp/Kconfig b/arch/arm/mach-zynqmp/Kconfig
index e4f2e24..f8b5906 100644
--- a/arch/arm/mach-zynqmp/Kconfig
+++ b/arch/arm/mach-zynqmp/Kconfig
@@ -25,6 +25,7 @@
 	default y if ZYNQ_QSPI
 
 config SYS_BOARD
+	string "Board name"
 	default "zynqmp"
 
 config SYS_VENDOR