media: siano: get rid of __le32/__le16 cast warnings

Those are all false-positives that appear with smatch when building for
arm:

  drivers/media/common/siano/smsendian.c:38:36: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:38:36: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:38:36: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:38:36: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:38:36: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:38:36: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:47:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:47:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:47:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:47:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:47:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:47:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:67:35: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:67:35: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:67:35: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:67:35: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:84:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:84:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:84:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:84:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:84:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:84:44: warning: cast to restricted __le32
  drivers/media/common/siano/smsendian.c:98:26: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:98:26: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:98:26: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:98:26: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:99:28: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:99:28: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:99:28: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:99:28: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:100:27: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:100:27: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:100:27: warning: cast to restricted __le16
  drivers/media/common/siano/smsendian.c:100:27: warning: cast to restricted __le16

Get rid of them by adding explicit forced casts.

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>