drivers/timers/rtc.c: Support signal notification through SIGEV_THREAD
drivers/input/ajoystick.c: Support signal notification through SIGEV_THREAD
drivers/input/djoystick.c: Support signal notification through SIGEV_THREAD
drivers/input/button_upper.c: Support signal notification through SIGEV_THREAD
drivers/sensors/zerocross.c: Support signal notification through SIGEV_THREAD
drivers/wireless/ieee802154: Support signal notification through SIGEV_THREAD
drivers/lcd/ft80x.c: Support signal notification through SIGEV_THREAD
Squashed commit of the following:
sched: Rename all use of system_t to clock_t.
syscall: Rename all use of system_t to clock_t.
net: Rename all use of system_t to clock_t.
libs: Rename all use of system_t to clock_t.
fs: Rename all use of system_t to clock_t.
drivers: Rename all use of system_t to clock_t.
arch: Rename all use of system_t to clock_t.
include: Remove definition of systime_t; rename all use of system_t to clock_t.
drivers/lcd/ft80x: ACTIVE host command appears to be formatted differently than other host commands; Fix ROM CHIPID. Appears to be big-ending, BCD.
drivers/lcd/ft80x: Fix some compile issues when debug features are enabled.
drivers/lcd and include/nuttx/lcd: Add FT80x support for writing to graphics memory. Also add some definitions needed by apps/examples/ft80x for bitmap manipulation.
drivers/lcd: Review/update FT80x initializatin logic
drivers/lcd: Rename ft80x_base.c to just ft80x.c. Add logic to notify FT80X clients of events via signals.
drivers/lcd: Trivial updates to naming. Add some new definitions.