video: exynos_dp: Improve EDID error handling

EDID error handling has 2 problems:
 - It doesn't fail as early as it can
 - The retry counts for i2c and aux transactions are huge

This patch fails if the initial i2c transaction fails, and reduces the
aux and i2c retry counts down to 3.

[jg1.han@samsung.com: reduced the retry count of exynos_dp_read_byte_from_dpcd()]
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Jingoo Han <jg1.han@samsung.com>