uapi linux/kfd_ioctl.h: only use __u32 and __u64

Include <drm/drm.h> instead of <linux/types.h> which on Linux includes
<linux/types.h> and on non-Linux platforms defines __u32 etc types.

Fixes user space compilation errors like:

linux/kfd_ioctl.h:33:2: error: unknown type name ‘uint32_t’
  uint32_t major_version; /* from KFD */
  ^~~~~~~~

Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>