system: core: fastboot: Increase USB protocol buffer size to 1024

With USB3.0 SS support the max packet size supported by USB protocol
is 1024 bytes. When connected to a USB device in SuperSpeed, if only
512 bytes are sent at a time the device would interpret each transfer
as a short packet and slows down overall throughput. To accommodate
for SuperSpeed USB bulk endpoints, increase the buffer size to 1024.

Change-Id: I4f447fe38045bc0008e2d6dd3f36c2d6819d6c15
Remove dead code.

Intel accidentally made this dead code in 2010 with commit
2bef93cc20155c3a59cdbb22c564c4b385b2c160, and no one's ever noticed.

Since no one noticing for so long implies that it doesn't matter,
let's just kill the supposedly optimized code.

Change-Id: Id5b37056cb8884c20bfe2db362e19b46f02e337d
Merge "system: core: fastboot: Increase USB protocol buffer size to 1024"
Merge "Remove dead code."