Gigabeat S: Revert removal of usb_plugged in r31489

Synchronous cable read is still required because the timing of the receipt of
the cable event cannot be known for sure-- basically it introduced a thread
race between main and pmic. If a keypress is desired instead to enter BL USB
mode a la AS3525, then it's possible to remove that.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@31510 a1c6a512-1295-4272-9138-f99709370657
3 files changed