dm: core: Create a new header file for 'compat' features

At present dm/device.h includes the linux-compatible features. This
requires including linux/compat.h which in turn includes a lot of headers.
One of these is malloc.h which we thus end up including in every file in
U-Boot. Apart from the inefficiency of this, it is problematic for sandbox
which needs to use the system malloc() in some files.

Move the compatibility features into a separate header file.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/lib/libavb/avb_cmdline.c b/lib/libavb/avb_cmdline.c
index 684c512..dd859d3 100644
--- a/lib/libavb/avb_cmdline.c
+++ b/lib/libavb/avb_cmdline.c
@@ -7,6 +7,7 @@
 #include "avb_sha.h"
 #include "avb_util.h"
 #include "avb_version.h"
+#include <malloc.h>
 
 #define NUM_GUIDS 3
 
diff --git a/lib/libavb/avb_descriptor.c b/lib/libavb/avb_descriptor.c
index 9f03b97..86b8d1b 100644
--- a/lib/libavb/avb_descriptor.c
+++ b/lib/libavb/avb_descriptor.c
@@ -6,6 +6,7 @@
 #include "avb_descriptor.h"
 #include "avb_util.h"
 #include "avb_vbmeta_image.h"
+#include <malloc.h>
 
 bool avb_descriptor_validate_and_byteswap(const AvbDescriptor* src,
                                           AvbDescriptor* dest) {
diff --git a/lib/libavb/avb_rsa.c b/lib/libavb/avb_rsa.c
index bbf1562..d7bf890 100644
--- a/lib/libavb/avb_rsa.c
+++ b/lib/libavb/avb_rsa.c
@@ -12,6 +12,7 @@
 #include "avb_sha.h"
 #include "avb_util.h"
 #include "avb_vbmeta_image.h"
+#include <malloc.h>
 
 typedef struct IAvbKey {
   unsigned int len; /* Length of n[] in number of uint32_t */
diff --git a/lib/libavb/avb_slot_verify.c b/lib/libavb/avb_slot_verify.c
index c0defdf..58baf52 100644
--- a/lib/libavb/avb_slot_verify.c
+++ b/lib/libavb/avb_slot_verify.c
@@ -14,6 +14,7 @@
 #include "avb_util.h"
 #include "avb_vbmeta_image.h"
 #include "avb_version.h"
+#include <malloc.h>
 
 /* Maximum number of partitions that can be loaded with avb_slot_verify(). */
 #define MAX_NUMBER_OF_LOADED_PARTITIONS 32
diff --git a/lib/libavb/avb_sysdeps_posix.c b/lib/libavb/avb_sysdeps_posix.c
index 0bb0cc1..6ffdb0b 100644
--- a/lib/libavb/avb_sysdeps_posix.c
+++ b/lib/libavb/avb_sysdeps_posix.c
@@ -4,6 +4,7 @@
  */
 
 #include <hang.h>
+#include <malloc.h>
 #include <stdarg.h>
 #include <stdlib.h>
 
diff --git a/lib/libavb/avb_util.c b/lib/libavb/avb_util.c
index 405d625..94773b7 100644
--- a/lib/libavb/avb_util.c
+++ b/lib/libavb/avb_util.c
@@ -4,6 +4,7 @@
  */
 
 #include "avb_util.h"
+#include <malloc.h>
 
 #include <stdarg.h>