FS #7691 - improved USB detection on PP devices.  This patch modifies the target-tree function usb_detect() on all targets from bool to int, returning USB_INSERTED or USB_EXTRACTED instead of true or false.  This was done to enable the PP usb_detect() to check for USB_POWER (either a connection to a USB wall charger, or the user holding "charge mode" button) and return that as a third value.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@14600 a1c6a512-1295-4272-9138-f99709370657
19 files changed