Fix a typo: s/wriable/writable/
Eliminate the gratuitous use of mmap(2) flags from the implementation
of kern_shmat().  Use a simpler approach to determine whether to pass
VMFS_NO_SPACE or VMFS_OPTIMAL_SPACE to vm_map_find().
Add support for Freescale Vybrid Family VF600 heterogeneous
ARM Cortex-A5/M4 SoC (M4 core is not used in this work).

Support includes device drivers for:
- NAND Flash Controller (NFC)
- USB Enhanced Host Controller Interface (EHCI)
- General-Purpose Input/Output (GPIO)
- Universal Asynchronous Receiver/Transmitter (UART)

Also supported:
- Generic Interrupt Controller (GIC)
- MPCore timer
- ffec ethernet driver

Reviewed by:	ray
Approved by:	cognet (mentor)