arm64: zynqmp: spl: use given boot_device instead of fetching it again

The boot_device argument to spl_boot_mode was massively added without
actually modifying the existing functions.

This commit actually makes use of the handed value, which is the same.

Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/arm/cpu/armv8/zynqmp/spl.c b/arch/arm/cpu/armv8/zynqmp/spl.c
index 6afa074..db7432f 100644
--- a/arch/arm/cpu/armv8/zynqmp/spl.c
+++ b/arch/arm/cpu/armv8/zynqmp/spl.c
@@ -112,7 +112,7 @@
 
 u32 spl_boot_mode(const u32 boot_device)
 {
-	switch (spl_boot_device()) {
+	switch (boot_device) {
 	case BOOT_DEVICE_RAM:
 		return 0;
 	case BOOT_DEVICE_MMC1: