MIPS: Loongson: Naming style cleanup and rework

Currently, code of Loongson-2/3 is under loongson directory and code of
Loongson-1 is under loongson1 directory. Besides, there are Kconfig
options such as MACH_LOONGSON and MACH_LOONGSON1. This naming style is
very ugly and confusing. Since Loongson-2/3 are both 64-bit general-
purpose CPU while Loongson-1 is 32-bit SoC, we rename both file names
and Kconfig symbols from loongson/loongson1 to loongson64/loongson32.

[ralf@linux-mips.org: Resolve a number of simple conflicts.]

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Kelvin Cheung <keguang.zhang@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/9790/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-loongson64/spaces.h

@@ -0,0 +1,9 @@
+#ifndef __ASM_MACH_LOONGSON64_SPACES_H_
+#define __ASM_MACH_LOONGSON64_SPACES_H_
+
+#if defined(CONFIG_64BIT)
+#define CAC_BASE        _AC(0x9800000000000000, UL)
+#endif /* CONFIG_64BIT */
+
+#include <asm/mach-generic/spaces.h>
+#endif