add module init wrappers

implement storage for commonly accessed parameters
implement parameter retrieval

fix generic radio upper half build

write ioctl dispatcher
indicate arg type for each ioctl

drivers/wireless/nrf24l01.c:  Review last PR.  Also got enthused and did major re-work to file to bring it closer to the NuttX coding style.  Fixed a few compile time warnings.

- signal POLLIN if there is already data in the FIFO
- send ETIMEDOUT to userspace after 2 seconds if TX IRQ was not received
- handle FIFO overflow
- handle invalid pipes/empty FIFO
- multiple cosmetics (missing static, duplicate define, missing \n)

stm32_gpiosetevent: GPIO IRQ logic no longer returns the xcpt_t oldhandler.  This value is useless and dangerous after the recent changes to interrupt argument passing.

Provide a user defined callback context for irq's, such that when
registering a callback users can provide a pointer that will get
passed back when the isr is called.

drivers/:  Remove all explicit use of 'hidden' macro _info.  Code must never use this directly.  Code must always use a debug macro such as info which is basic on _info but can be appropriately filtered.