linux-user: Move get_elf_cpu_model to target/elfload.c

Rename from cpu_get_model to emphasize that this is an elf-specific
function.  Declare the function once in loader.h.

This frees up target_elf.h for other uses.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
39 files changed