zynq: Increase the early malloc() size

This is needed to support driver-model conversion of USB and block devices.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/cpu/armv8/zynqmp/Kconfig b/arch/arm/cpu/armv8/zynqmp/Kconfig
index 6c71d78..ed3305d 100644
--- a/arch/arm/cpu/armv8/zynqmp/Kconfig
+++ b/arch/arm/cpu/armv8/zynqmp/Kconfig
@@ -20,4 +20,8 @@
 config ZYNQMP_USB
 	bool "Configure ZynqMP USB"
 
+config SYS_MALLOC_F_LEN
+	default 0x600
+
+
 endif