Rename nand.h as flash/nand/core.h, chase consumers.  The public APIs
need to be sorted out with imp.h, but this allows other changes to
begin improving the separation between policy and mechanism.

Moves #include <target/target.h> and #include "driver.h" into the
internal headers or source files, removing it from <flash/nand/core.h>.

Move remaining NAND implementation files into src/flash/nand/.

Moves commands into nand/tcl.c and core implementation to 'nand/core.c'
and 'nand/fileio.c'.  Eliminates 'flash/nand.c'.

Adds 'nand/imp.h' to share routines between TCL commands and core.

This work parallels the NOR directory, encapsulating the NAND drivers
into a separate file.  This takes an extra step by encapsulating the
type of data structure used to manage the drivers, allowing it to be
changed from an array to a dynamic list in the future.

Modify the arm_nand_data struct to better support both read and
write operations while using the same struct.  An additional
field was added, and initialized, to record the last operation
so that the correct code can be loaded to the working area.

[dbrownell@users.sourceforge.net: merge init patch, tweak GPL note]

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>

With all #include directives converted, we only need to have the
top-level src/ directory in the search path.

Before we can -I the top-level src/ directory alone, references to
"hello.h" must be updated.  This is an internal header, so it does
not need angle brackets.

Changes from the flat namespace to heirarchical one.  Instead of writing:

	#include "s3c24xx_regs.h"

the following form should be used.

	#include <flash/nand/s3c24xx_regs.h>

The exception is from .c files in the same directory.

Changes from the flat namespace to heirarchical one.  Instead of writing:

	#include "nand.h"

the following form should be used.

	#include <flash/nand.h>

The exception is from .c files in the same directory.

Changes from the flat namespace to heirarchical one.  Instead of writing:

	#include "arm_nandio.h"

the following form should be used.

	#include <flash/arm_nandio.h>

The exception is from .c files in the same directory.

Changes from the flat namespace to heirarchical one.  Instead of writing:

	#include "armv4_5.h"

the following form should be used.

	#include <target/armv4_5.h>

The exception is from .c files in the same directory.

These headers need minor tweaks to paves the way for wholesale
scripted coversion of the header files.

Includes the src directory in the search path, so header files may be
migrated from:

  #include "foo.h"

to
  #include <module/foo.h>

which is more conducive for installation.

Moves NAND drivers to src/flash/nand/.
Adds src/flash/nand/Makefile.am.
Builds libocdflashnand.la.