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>
diff --git a/arch/mips/configs/loongson3_defconfig b/arch/mips/configs/loongson3_defconfig
index c844299..f8bf915c 100644
--- a/arch/mips/configs/loongson3_defconfig
+++ b/arch/mips/configs/loongson3_defconfig
@@ -1,4 +1,4 @@
-CONFIG_MACH_LOONGSON=y
+CONFIG_MACH_LOONGSON64=y
 CONFIG_SWIOTLB=y
 CONFIG_LOONGSON_MACH3X=y
 CONFIG_CPU_LOONGSON3=y