powerpc: Work around ld bug in older binutils

Commit 549e8152 ("powerpc: Make the
64-bit kernel as a position-independent executable") added lines to
vmlinux.lds.S to add the extra sections needed to implement a
relocatable kernel.  However, those lines seem to trigger a bug in
older versions of GNU ld (such as 2.16.1) when building a
non-relocatable kernel.  Since ld 2.16.1 is still a popular choice for
cross-toolchains, this adds an #ifdef to vmlinux.lds.S so the added
lines are only included when building a relocatable kernel.
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/vmlinux.lds.S

@@ -187,6 +187,7 @@ SECTIONS
 		*(.machine.desc)
 		__machine_desc_end = . ;
 	}
+#ifdef CONFIG_RELOCATABLE
 	. = ALIGN(8);
 	.dynsym : AT(ADDR(.dynsym) - LOAD_OFFSET) { *(.dynsym) }
 	.dynstr : AT(ADDR(.dynstr) - LOAD_OFFSET) { *(.dynstr) }
@@ -202,6 +203,7 @@ SECTIONS
 		__rela_dyn_start = .;
 		*(.rela*)
 	}
+#endif
 
 	/* Fake ELF header containing RPA note; for addnote */
 	.fakeelf : AT(ADDR(.fakeelf) - LOAD_OFFSET) { *(.fakeelf) }