spl: Rename SYS_SPL_ARGS_ADDR to SPL_PAYLOAD_ARGS_ADDR

Rename this so that SPL is first, as per U-Boot convention. Also add
PAYLOAD_ since this is where in memory the parameters for the payload
have been stored.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/display5_defconfig b/configs/display5_defconfig
index 496fd4a..24f22f0 100644
--- a/configs/display5_defconfig
+++ b/configs/display5_defconfig
@@ -45,7 +45,7 @@
 CONFIG_SPL_SAVEENV=y
 CONFIG_SPL_I2C=y
 CONFIG_SPL_OS_BOOT=y
-CONFIG_SYS_SPL_ARGS_ADDR=0x18000000
+CONFIG_SPL_PAYLOAD_ARGS_ADDR=0x18000000
 CONFIG_SPL_FALCON_BOOT_MMCSD=y
 CONFIG_SYS_MMCSD_RAW_MODE_KERNEL_SECTOR=0x100
 CONFIG_SYS_MMCSD_RAW_MODE_ARGS_SECTOR=0x3F00