hw/loader: Pass ELFDATA endian order argument to load_elf()

hw/loader: Pass ELFDATA endian order argument to load_elf()

Rather than passing a boolean 'is_big_endian' argument,
directly pass the ELFDATA, which can be unspecified using
the ELFDATANONE value.

Update the call sites:
  0                 -> ELFDATA2LSB
  1                 -> ELFDATA2MSB
  TARGET_BIG_ENDIAN -> TARGET_BIG_ENDIAN ? ELFDATA2MSB : ELFDATA2LSB

Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: BALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250127113824.50177-7-philmd@linaro.org>