[cherryusb][ehci] Fix missing SETUP buffer cache clean

Backport cherry-embedded/CherryUSB@41f5796:
https://github.com/cherry-embedded/CherryUSB/commit/41f57964cc442145099250f0190eb71e9d1d9d5a

The fix is already merged in CherryUSB upstream but is not included in
the v1.6.1 copy integrated in RT-Thread.  The EHCI port cleans qTD/QH
descriptors and the transfer buffer for DMA, but not the SETUP packet,
so on a non-coherent platform the controller can read a stale packet and
a device may never enumerate.

Apply the upstream change: clean the SETUP buffer in ehci_qh_add_head()
before the QH is linked into the asynchronous or periodic list.

0 files changed, 0 insertions, 0 deletions