drm/displayid: Iterate over all DisplayID blocks

This will iterate over all DisplayID blocks found in the buffer.
Previously only the first block was parsed.

https://bugs.freedesktop.org/show_bug.cgi?id=95207



Change-Id: Ida0480aa1652d3725a02950df83c3602fce8bb6e
Signed-off-by: Tomas Bzatek <tomas@bzatek.net>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Git-commit: 3a4a2ea39f86c581054794c0a727597745f1084b
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Abhinav Kumar <abhinavk@codeaurora.org>