sparc: remove obsolete documentation

When we killed btfixup this readme no longer has any value.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/sparc/README-2.5

-BTFIXUP
--------
-
-To build new kernels you have to issue "make image". The ready kernel
-in ELF format is placed in arch/sparc/boot/image. Explanation is below.
-
-BTFIXUP is a unique feature of Linux/sparc among other architectures,
-developed by Jakub Jelinek (I think... Obviously David S. Miller took
-part, too). It allows to boot the same kernel at different 
-sub-architectures, such as sun4c, sun4m, sun4d, where SunOS uses
-different kernels. This feature is convinient for people who you move
-disks between boxes and for distrution builders.
-
-To function, BTFIXUP must link the kernel "in the draft" first,
-analyze the result, write a special stub code based on that, and
-build the final kernel with the stub (btfix.o).
-
-Kai Germaschewski improved the build system of the kernel in the 2.5 series
-significantly. Unfortunately, the traditional way of running the draft
-linking from architecture specific Makefile before the actual linking
-by generic Makefile is nearly impossible to support properly in the
-new build system. Therefore, the way we integrate BTFIXUP with the
-build system was changed in 2.5.40. Now, generic Makefile performs
-the draft linking and stores the result in file vmlinux. Architecture
-specific post-processing invokes BTFIXUP machinery and final linking
-in the same way as other architectures do bootstraps.
-
-Implications of that change are as follows.
-
-1. Hackers must type "make image" now, instead of just "make", in the same
-   way as s390 people do now. It is analogous to "make bzImage" on i386.
-   This does NOT affect sparc64, you continue to use "make" to build sparc64
-   kernels.
-
-2. vmlinux is not the final kernel, so RPM builders have to adjust
-   their spec files (if they delivered vmlinux for debugging).
-   System.map generated for vmlinux is still valid.
-
-3. Scripts that produce a.out images have to be changed. First, if they
-   invoke make, they have to use "make image". Second, they have to pick up
-   the new kernel in arch/sparc/boot/image instead of vmlinux.
-
-4. Since we are compliant with Kai's build system now, make -j is permitted.
-
--- Pete Zaitcev
-zaitcev@yahoo.com