usb: re-enable EHCI, share HID keyboard decoding, fix boot protocol

- ehci: DEBUG_MATRIX was left true in be868a4, so every boot replaced
  enumeration with the one-shot diagnostic transfer matrix and returned
  false -- the EHCI driver never brought a device up.  Default it off;
  flip it back on only when bisecting a controller fault.
- new rsnix/src/hid.rs: boot-keyboard HID usage -> scancode-set-1
  tables, the shared scancode FIFO, and a per-device report differ.
  UHCI now uses it instead of its own copy, so EHCI/xHCI keyboards can
  feed the same PS/2 decoder (`ps2::feed_scancode`).
- uhci: SET_PROTOCOL now asks for the boot protocol (wValue 0) instead
  of report protocol (wValue 1).  In report protocol the report layout
  is device-defined, but every driver parses boot reports.

1 files changed, 1 insertions, 0 deletions

diff --git a/rsnix/src/lib.rs b/rsnix/src/lib.rs
index 325932a..b4307a3 100644
--- a/rsnix/src/lib.rs
+++ b/rsnix/src/lib.rs
@@ -11,6 +11,7 @@ pub mod font;
 pub mod fs;
 pub mod gdt;
 pub mod gop;
+pub mod hid;
 pub mod interrupts;
 pub mod klog;
 pub mod load;