hw/mips/loongson3_bootp: Include missing headers

hw/mips/loongson3_bootp: Include missing headers

MemMapEntry is declared in "exec/hwaddr.h", cpu_to_le32() in
"qemu/bswap.h". These headers are indirectly included via "cpu.h".
Include them explicitly in order to avoid when removing "cpu.h":

  In file included from ../../hw/mips/loongson3_bootp.c:27:
  hw/mips/loongson3_bootp.h:234:14: error: unknown type name 'MemMapEntry'
    234 | extern const MemMapEntry virt_memmap[];
        |              ^
  hw/mips/loongson3_bootp.c:33:18: error: call to undeclared function 'cpu_to_le32'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     33 |     c->cputype = cpu_to_le32(Loongson_3A);
        |                  ^

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250115232952.31166-6-philmd@linaro.org>