usb: fix support for HID keyboard

This fixes issues with several HID keyboards by implementing
get_unaligned_le16(), which obviously may also fix other not-yet-known
issues. Hint: I had to look out for suspicious lines like follows in the
verbose log.

  [init -> usb_drv] get_unaligned_le16 called, not implemented

Also, quirks for cherry keyboards are now applied.
cli_monitor: Support dynamically linked binaries
terminal: Add escape handling for CUB

This VT102 command is triggered by busybox when pressing the 'pos1' key.
terminal_mux: Clear terminal when activating menu

This patch clears the terminal each time the menu appears and thereby
wipes away artifacts that might occur when combining terminal_mux with
kdb_uart_drv and the kernel prints messages directly.
Add missing route to timer
sd_card: Support multiple DMA descriptors
New 'l4linux_dynamic.run' script

This run script allows the user to dynamically start and stop L4Linux
instances using a command-line interface over a serial line.