powerpc: Enable additional BAT registers in setup_745x_specifics()

Currently the kernel expects the additional four IBAT and DBAT registers
to be available, but doesn't enable these registers on 745x CPUs, which
have them disabled after reset. Thus set the HIGH_BAT_EN bit in HID0
register, if the corresponding MMU feature is defined.
Signed-off-by: Gerhard Pircher <gerhard_pircher@gmx.net>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/kernel/cpu_setup_6xx.S

@@ -239,6 +239,9 @@ END_FTR_SECTION_IFSET(CPU_FTR_L3CR)
 	ori	r11,r11,HID0_SGE | HID0_FOLD | HID0_BHTE
 	ori	r11,r11,HID0_LRSTK | HID0_BTIC
 	oris	r11,r11,HID0_DPM@h
+BEGIN_MMU_FTR_SECTION
+	oris	r11,r11,HID0_HIGH_BAT@h
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
 BEGIN_FTR_SECTION
 	xori	r11,r11,HID0_BTIC
 END_FTR_SECTION_IFSET(CPU_FTR_NO_BTIC)