[uaccess] Reduce scope of included uaccess.h header

The uaccess.h header is no longer required for any code that touches
external ("user") memory, since such memory accesses are now performed
through pointer dereferences.  Reduce the number of files including
this header.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/include/ipxe/dhcp.h

@@ -17,7 +17,6 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/tables.h>
 #include <ipxe/uuid.h>
 #include <ipxe/netdevice.h>
-#include <ipxe/uaccess.h>
 
 struct interface;
 struct dhcp_options;

src/include/ipxe/image.h

@@ -12,7 +12,6 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <ipxe/tables.h>
 #include <ipxe/list.h>
-#include <ipxe/uaccess.h>
 #include <ipxe/refcnt.h>
 
 struct uri;

src/include/ipxe/iomap.h

@@ -14,7 +14,6 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <stdint.h>
 #include <ipxe/api.h>
 #include <config/ioapi.h>
-#include <ipxe/uaccess.h>
 
 /**
  * Calculate static inline I/O mapping API function name

src/include/ipxe/iomap_virt.h

@@ -10,6 +10,7 @@
 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <stddef.h>
+#include <ipxe/uaccess.h>
 
 #ifdef IOMAP_VIRT
 #define IOMAP_PREFIX_virt

src/include/ipxe/xen.h

@@ -14,7 +14,6 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 
 #include <stdint.h>
 #include <ipxe/bitops.h>
-#include <ipxe/uaccess.h>
 #include <xen/xen.h>
 #include <xen/event_channel.h>