riscv: bootm: Add dm_remove_devices_flags() call to do_bootm_linux()

This adds a call to dm_remove_devices_flags() to do_bootm_linux()
so that drivers that have one of the removal flags set (e.g.
DM_FLAG_ACTIVE_DMA_REMOVE) in their driver struct, may do some
last-stage cleanup before the OS is started.

arm and x86 already did such, and we should do the same for riscv.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/riscv/lib/bootm.c b/arch/riscv/lib/bootm.c
index a7a9fb9..2b5ccce 100644
--- a/arch/riscv/lib/bootm.c
+++ b/arch/riscv/lib/bootm.c
@@ -9,9 +9,11 @@
 #include <common.h>
 #include <command.h>
 #include <image.h>
-#include <u-boot/zlib.h>
 #include <asm/byteorder.h>
 #include <asm/csr.h>
+#include <dm/device.h>
+#include <dm/root.h>
+#include <u-boot/zlib.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -57,6 +59,13 @@
 	/* we assume that the kernel is in place */
 	printf("\nStarting kernel ...\n\n");
 
+	/*
+	 * Call remove function of all devices with a removal flag set.
+	 * This may be useful for last-stage operations, like cancelling
+	 * of DMA operation or releasing device internal buffers.
+	 */
+	dm_remove_devices_flags(DM_REMOVE_ACTIVE_ALL);
+
 	cleanup_before_linux();
 
 	if (IMAGE_ENABLE_OF_LIBFDT && images->ft_len)