powerpc: Fix interrupt range check on debug exception

We do not want to take single step and branch-taken debug exception
in kernel exception code. But the address range check was not covering
all kernel exception handlers address range.

With this patch we defined the interrupt_end label which defines the
end on kernel exception code. So now we check interrupt_base to
interrupt_end range for not handling debug exception in kernel
exception entry.

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/head_fsl_booke.S

@@ -605,6 +605,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_EMB_HV)
 	/* Embedded Hypervisor Privilege */
 	EXCEPTION(0, HV_PRIV, Ehvpriv, unknown_exception, EXC_XFER_EE)
 
+interrupt_end:
+
 /*
  * Local functions
  */