microblaze: Use malloc setting via Kconfig

Clean board specific file.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/microblaze-generic_defconfig b/configs/microblaze-generic_defconfig
index 1fe2e0f..98391c8 100644
--- a/configs/microblaze-generic_defconfig
+++ b/configs/microblaze-generic_defconfig
@@ -1,4 +1,6 @@
 CONFIG_MICROBLAZE=y
+CONFIG_SYS_MALLOC_F=y
+CONFIG_SPL_SYS_MALLOC_SIMPLE=y
 CONFIG_TARGET_MICROBLAZE_GENERIC=y
 CONFIG_DEFAULT_DEVICE_TREE="microblaze-generic"
 CONFIG_SPL=y