sparc64: move EXPORT_SYMBOL to the symbols definition

Move all applicable EXPORT_SYMBOL()s to the file where the respective
symbol is defined.

Removed all the includes that are no longer needed in sparc_ksyms_64.c

Comment all remaining EXPORT_SYMBOL()s in sparc_ksyms_64.c

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>

Additions by Julian Calaby:
* Moved EXPORT_SYMBOL()s for prom functions to their rightful places.
* Made some minor cleanups to the includes and comments of sparc_ksyms_64.c
* Updated and tidied commit message.
* Rebased patch over sparc-2.6.git HEAD.
* Ensured that all modified files have the correct includes.

Signed-off-by: Julian Calaby <julian.calaby@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>