[POWERPC] Rename MPIC_BROKEN_U3 to MPIC_U3_HT_IRQS

Rename MPIC_BROKEN_U3 to something a little more descriptive. Its
effect is to enable support for HT irqs behind the PCI-X/HT bridge on
U3/U4 (aka. CPC9x5) parts.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig
index a8da0ae..126b9f8 100644
--- a/arch/powerpc/configs/ppc64_defconfig
+++ b/arch/powerpc/configs/ppc64_defconfig
@@ -152,7 +152,7 @@
 CONFIG_RTAS_PROC=y
 CONFIG_RTAS_FLASH=m
 CONFIG_MMIO_NVRAM=y
-CONFIG_MPIC_BROKEN_U3=y
+CONFIG_MPIC_U3_HT_IRQS=y
 CONFIG_IBMVIO=y
 # CONFIG_IBMEBUS is not set
 # CONFIG_PPC_MPC106 is not set