Linux 4.9 config: disable vmapped stack until drivers are fixed

[mglae]

Using the new linux 4.9 vmapped stack feature crashes all drivers still using DMA buffers on stack. In case of the USB 'TechnoTrend TT-connect S2-4600' the error is

transfer buffer not dma capable

dmesg: http://sprunge.us/BMNN

Background information can be found on LWN.net and Phoronix.

With this PR the driver loads fine and at least the remote is working. Full test is not possible as I currently have no access to a dish.

@CvH: if still motivated you may give the TBS drivers a last chance :-)

[CvH]

@mglae the tbs drivers has other problems ;) (for a kind of fix see #1073)
Tx that you report this, 2 devices were reported that stacktraces - both with this message (T230 for example). I build and test image (usual place) to see if this fixes it for them too.

Gianatech T230 for example

vb-usb: found a 'Mygica T230 DVB-T/T2/C' in warm state.
TL871X: module init start
TL871X: rtl8812au v4.3.20_16317.20160108
TL871X: build time: Dec 15 2016 13:32:05
-----------[ cut here ]------------
ARNING: CPU: 1 PID: 280 at drivers/usb/core/hcd.c:1584 usb_hcd_map_urb_for_dma+0x370/0x550
ransfer buffer not dma capable
odules linked in: 8812au(O+) dvb_usb_cxusb(O+) dib0070(O) dvb_usb(O) rc_core(O) dvb_core(O) cfg80211 media(O) snd_usb_audio snd_hwdep snd_usbmidi_lib snd_rawmidi
PU: 1 PID: 280 Comm: systemd-udevd Tainted: G           O    4.9.0 #1
ardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./To be filled by O.E.M., BIOS 080016  03/16/2011
0000000000000000 ffffffff81388194 ffffc90000dc7900 0000000000000000
ffffffff8104a7b4 ffff88005d587780 ffffc90000dc7950 0000000000000000
0000000002400000 0000000000000000 0000000000000002 ffffffff8104a81a
Call Trace:
[<ffffffff81388194>] ? dump_stack+0x5c/0x78
[<ffffffff8104a7b4>] ? __warn+0xb4/0xd0
[<ffffffff8104a81a>] ? warn_slowpath_fmt+0x4a/0x50
[<ffffffff8109a466>] ? lock_timer_base+0x76/0x90
[<ffffffff818e8dc0>] ? usb_hcd_map_urb_for_dma+0x370/0x550
[<ffffffff818e9e59>] ? usb_hcd_submit_urb+0x2e9/0x940

[CvH]

reported working for various DVB cards, should go in (if nobody has objections) before 010 ;)