m68k/sun3: Remove define statement no longer needed

In the file sun3_pgalloc.h we should remove #define_KERNPG_TABLE equals 0
as this define statement hasn't been used since kernel verison 2.5.18 and
is now no longer needed.

Signed-off-by: Nicholas Krause <xerofoify@gmail.com>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>