MIPS: jazz: always allow little-endian builds

The kernel test robot keeps reporting the same bug when it
shows up in new files after random unrelated patches:

In file included from arch/mips/include/uapi/asm/byteorder.h:13,
from arch/mips/include/asm/bitops.h:20,
from include/linux/bitops.h:26,
from include/linux/kernel.h:12,
from include/linux/clk.h:13,
from drivers/base/regmap/regmap-mmio.c:7:
include/linux/byteorder/big_endian.h:8:2: warning: #warning inconsistent configuration, needs CONFIG_CPU_BIG_ENDIAN [-Wcpp]
8 | #warning inconsistent configuration, needs CONFIG_CPU_BIG_ENDIAN
| ^~~~~~~
drivers/base/regmap/regmap-mmio.c: In function 'regmap_mmio_gen_context':
>> drivers/base/regmap/regmap-mmio.c:274:2: error: duplicate case value
274 | case REGMAP_ENDIAN_NATIVE:
| ^~~~
drivers/base/regmap/regmap-mmio.c:246:2: note: previously used here
246 | case REGMAP_ENDIAN_NATIVE:

The problem is that some randconfig builds end up on the MIPS jazz
platform with neither CONFIG_CPU_BIG_ENDIAN nor CONFIG_CPU_LITTLE_ENDIAN
because no specific machine is selected. As it turns out, all jazz
machines support little-endian kernels, so this can simply be allowed
globally.

Reported-by: kernel test robot <[e-mail]>
Signed-off-by: Arnd Bergmann <[e-mail]>
Signed-off-by: Thomas Bogendoerfer <[e-mail]>

arch/mips/Kconfig

···
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_100HZ
+	select SYS_SUPPORTS_LITTLE_ENDIAN
 	help
 	  This a family of machines based on the MIPS R4030 chipset which was
 	  used by several vendors to build RISC/os and Windows NT workstations.

arch/mips/jazz/Kconfig

···
 	bool "Support for Acer PICA 1 chipset"
 	depends on MACH_JAZZ
 	select DMA_NONCOHERENT
-	select SYS_SUPPORTS_LITTLE_ENDIAN
 	help
 	  This is a machine with a R4400 133/150 MHz CPU. To compile a Linux
 	  kernel that runs on these, say Y here. For details about Linux on
···
 	depends on MACH_JAZZ
 	select DMA_NONCOHERENT
 	select SYS_SUPPORTS_BIG_ENDIAN
-	select SYS_SUPPORTS_LITTLE_ENDIAN
 	help
 	  This is a machine with a R4000 100 MHz CPU. To compile a Linux
 	  kernel that runs on these, say Y here. For details about Linux on
···
 	bool "Support for Olivetti M700-10"
 	depends on MACH_JAZZ
 	select DMA_NONCOHERENT
-	select SYS_SUPPORTS_LITTLE_ENDIAN
 	help
 	  This is a machine with a R4000 100 MHz CPU. To compile a Linux
 	  kernel that runs on these, say Y here. For details about Linux on