m32r: build fix of entry.S

This patch fixes the following compile error:
<--  snip  -->
 ...
  AS      arch/m32r/kernel/entry.o
/home/bunk/linux/kernel-2.6/linux-2.6.23-rc3-mm1/arch/m32r/kernel/entry.S: Assembler messages:
/home/bunk/linux/kernel-2.6/linux-2.6.23-rc3-mm1/arch/m32r/kernel/entry.S:358: Error: bad instruction `addi r0,#(((((0)+(64))+(32))+(32)))'
make[2]: *** [arch/m32r/kernel/entry.o] Error 1
<--  snip  -->

Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Cc: Adrian Bunk <bunk@kernel.org>