powerpc: Clean ifdef usage in copy_thread()

Currently, a single ifdef covers SLB related bits and more generic ppc64
related bits, split this in two separate ifdef's since 64-bit BookE will
need one but not the other.

Signed-off-by: Benjamin Herrenschmidt <[e-mail]>
Acked-by: Benjamin Herrenschmidt <[e-mail]>

arch/powerpc/kernel/process.c

···
 		sp_vsid |= SLB_VSID_KERNEL | llp;
 		p->thread.ksp_vsid = sp_vsid;
 	}
+#endif /* CONFIG_PPC_STD_MMU_64 */
 
 	/*
 	 * The PPC64 ABI makes use of a TOC to contain function 
···
 	 * to the TOC entry.  The first entry is a pointer to the actual
 	 * function.
  	 */
+#ifdef CONFIG_PPC64
 	kregs->nip = *((unsigned long *)ret_from_fork);
 #else
 	kregs->nip = (unsigned long)ret_from_fork;