How to disable Altivec registers in powerpc GDB ?

I've built gdb 6.9 using --target=powerpc-eabi

gdb appears to think that my target has the altivec vector registers,
although it does not. It is a Freescale MPC5xxx embedded part.

e.g. when trying to debug the embedded target via Eclipse, I'm seeing
this:
(gdb) 
5624-data-list-register-names
5624^done,register-names=["r0","r1","r2","r3","r4","r5","r6","r7","r8","r9","r10","r11","r12","r13","r14","r15","r16","r17","r18","r19","r20","r21","r22","r23","r24","r25","r26","r27","r28","r29","r30","r31","f0","f1","f2","f3","f4","f5","f6","f7","f8","f9","f10","f11","f12","f13","f14","f15","f16","f17","f18","f19","f20","f21","f22","f23","f24","f25","f26","f27","f28","f29","f30","f31","pc","msr","cr","lr","ctr","xer","fpscr","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","","vr0","vr1","vr2","vr3","vr4","vr5","vr6","vr7","vr8","vr9","vr10","vr11","vr12","vr13","vr14","vr15","vr16","vr17","vr18","vr19","vr20","vr21","vr22","vr23","vr24","vr25","vr26","vr27","vr28","vr29","vr30","vr31","vscr","vrsave","","","","","","","","","","","","
 ","","","","","","","","","","","","","","","","","","","","","dl0","dl1","dl2","dl3","dl4","dl5","dl6","dl7","dl8","dl9","dl10","dl11","dl12","dl13","dl14","dl15"]
(gdb)

The target doesn't have that many registers and the remote debugger
returns an error code and drops the gdb connection if any are accessed.
I'd like gdb to only report the basic 32 GPRs and 8 specials.

I've searched online a fair bit and through the archives of this mailing
list without finding any obvious solutions.

The source appears to make reference to gdbarch determining whether
these features are enabled or not but I don't know how to use it.

I built the .elf file I'm debugging using gcc - are there any flag that
I should have set there that determine the vector register ABI that are
then used by gdb?

Any help appreciated.

regards

James Murray