LoongArch: Adjust default config files for 32BIT/64BIT

Add loongson32_defconfig (for 32BIT) and rename loongson3_defconfig to
loongson64_defconfig (for 64BIT).

Also adjust graphics drivers, such as FB_EFI is replaced with EFIDRM.

Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Author: chenhuacai

arch/loongarch/Makefile

@@ -5,7 +5,12 @@
 
 boot	:= arch/loongarch/boot
 
-KBUILD_DEFCONFIG := loongson3_defconfig
+ifeq ($(shell uname -m),loongarch32)
+KBUILD_DEFCONFIG := loongson32_defconfig
+else
+KBUILD_DEFCONFIG := loongson64_defconfig
+endif
+
 KBUILD_DTBS      := dtbs
 
 image-name-y			:= vmlinux