MIPS: Loongson: Add basic Loongson 2F support

Loongson 2F has built-in DDR2 and PCI-X controller. The PCI-X controller
has a programming interface similiar to the the FPGA northbridge used on
Loongson 2E.

The main differences between Loongson 2E and Loongson 2F include:

1. Loongson 2F has an extra address window configuration module, which
   is used to map CPU address space to DDR or PCI address space, or map
   the PCI-DMA address space to DDR or LIO address space.

2. Loongson 2F supports 8 levels of software configurable CPu frequency
   which can be configured in the LOONGSON_CHIPCFG0 register.  The coming
   cpufreq and standby support are based on this feature.

Loongson.h abstracts the modules and corresponding methods are abstracted.

Add other Loongson-2F-specific source code including gcc 4.4 support, PCI
memory space, PCI IO space, DMA address.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index a16b6df..9618451 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1073,6 +1073,21 @@
 	  The Loongson 2E processor implements the MIPS III instruction set
 	  with many extensions.
 
+	  It has an internal FPGA northbridge, which is compatiable to
+	  bonito64.
+
+config CPU_LOONGSON2F
+	bool "Loongson 2F"
+	depends on SYS_HAS_CPU_LOONGSON2F
+	select CPU_LOONGSON2
+	help
+	  The Loongson 2F processor implements the MIPS III instruction set
+	  with many extensions.
+
+	  Loongson2F have built-in DDR2 and PCIX controller. The PCIX controller
+	  have a similar programming interface with FPGA northbridge used in
+	  Loongson2E.
+
 config CPU_MIPS32_R1
 	bool "MIPS32 Release 1"
 	depends on SYS_HAS_CPU_MIPS32_R1
@@ -1317,6 +1332,9 @@
 config SYS_HAS_CPU_LOONGSON2E
 	bool
 
+config SYS_HAS_CPU_LOONGSON2F
+	bool
+
 config SYS_HAS_CPU_MIPS32_R1
 	bool