[kernel][uart] Report ZX_ERR_NOT_SUPPORTED if no uart

Don't log an error in the UART console if no UART to read from.

Change-Id: I2319146d4a331d5c67439c90e1ca7dc86e0e28bf

[syscalls][debug] tweak zx_debug_read() to take an in/out arg and return status

Looks like was a leftover old skool syscall that returned int from the
left side instead of status_t. Update to be more up to date with the
current syscall style.

Also switch to taking a char * to be consistent with what it was already
doing.

Change-Id: I06f85510cb7d94ed10d0769b11c714a5b61b5be2

[system][dev][console] stop the debug reader from looping if the kernel is not returning chars

Change-Id: Ieed503ebbf9e71693d64a3777ddeb9d00cf44903

[ddk] Remove driver bind() cookie and unbind() callback

Also removed "owner" and "owner_cookie" from internal zx_device_t struct

Adjusted intel-hda audio drivers to create devices to hold driver context
rather than using the driver bind cookie.

Change-Id: I0eca7f6fa3b155be71843291812e7aa9fea5bf55

[dev] Rename "mxdev" to "zxdev" in ddktl and various drivers.

Change-Id: I000e42c26d9f8379de40447690694a35f6be93e2

[zx] Magenta -> Zircon

The Great Renaming is here!

Change-Id: I3229bdeb2a3d0e40fb4db6fec8ca7d971fbffb94

[dev][console] return correct number of bytes written

Change-Id: Ie7b3e2d32c597577b317bfad32905768b529c5ee

[dev][misc] Use new magenta error names

Change-Id: Ic468b633392b3a1a89d41d019437761d2b0eec3d

[udev][console] rename udev/console to dev/misc/console

Change-Id: I5b4bf1b9e32a5d66ef623af6f9a8a5aa12e4ac58