Upstream kinetis

Approved-by: Gregory Nutt

  Added K66 FMC register definition

   Added ALT version of RNGA, FTM2, DAC0 as a facility to later
   define secondary access via AIPS1 to these peripherals

  The K whole family line has max 4 or each. But the supported
  parts have the maximums listed below:

    K46 and K66    3 SPI SPI0-SPI2
    K46 and K66    4 I2C I2C0-I2C3

fs/inode/inode.h:  Fix a warning 'inode/inode.h:264:45: error: 'struct stat' declared inside parameter list' by adding a forward reference to struct stat.  Noted by David Sidrane.

ROMFS: Back out 29028bcd.  A cool idea, but loses the EXECUTABLE bit in the file type.

FAT: Fix some errors that I introduced in my review of Alan's patch.  My screw-up, not Alan's.  Sorry.

romfs:  Simplify fstat() implementation.  It is not necessary to save the file type at open,  We know in this context that the file is a regular file.

I found an issue inside the cp15_coherent_dcache function in file, arch/arm/src/armv7-r/cp15_coherent_dcache.S.

The "mcr CP15_BPIALLIS(r0)" instruction is used for invalidating entire branch predictor.  But the problem is, since this is the generic code and can be called on any armv7-r architecture based CPU's.  It is a problem, if this instruction is called in uni processor configuration. Because, BPIALLIS (c7, 0, c1, 6) instruction is only added as part of the "Multiprocessing Extensions" (As per ARM® Architecture Reference Manual /ARMv7-A and ARMv7-R edition)

So in my opinion, this instruction should be under SMP configuration. In non-SMP configuration this instruction could become undefined.

rename(): Correct more issues.  (1) Move to the root directory in the pseudo file system, (2) Fix path naming calculation when the path is the root directory of a mounted file system, and (3) dont't do the rename if the source and destination of the rename are the same.

Add logic to VFS rename:  If target of rename exists and is a directory, then the source file should be moved 'under' the target directory.  POSIX also requires that if the target is a file, then that old file must be deleted.