linux-user: Introduce imgsrc_read, imgsrc_read_alloc

Introduced and initialized, but not yet really used.
These will tidy the current tests vs BPRM_BUF_SIZE.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2 files changed