xilinx: drivers: Use '_' instead of '-' in driver name

The most of drivers are using '_' instead of '-' in driver name. That's why
sync up these names to be aligned. It looks quite bad to see both in use.
It is visible via dm tree command.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/clk/clk_zynqmp.c b/drivers/clk/clk_zynqmp.c
index 2313ac0..7795119 100644
--- a/drivers/clk/clk_zynqmp.c
+++ b/drivers/clk/clk_zynqmp.c
@@ -710,7 +710,7 @@
 };
 
 U_BOOT_DRIVER(zynqmp_clk) = {
-	.name = "zynqmp-clk",
+	.name = "zynqmp_clk",
 	.id = UCLASS_CLK,
 	.of_match = zynqmp_clk_ids,
 	.probe = zynqmp_clk_probe,