drm/amd/display: Fix misleading buffer information

RETIMER_REDRIVER_INFO shows the buffer as a decimal value with a '0x'
prefix, which is somewhat misleading.

Fix it to print hexadecimal, as was intended.

Fixes: 2f14bc89("drm/amd/display: add retimer log for HWQ tuning use.")
Cc: Charlene Liu <charlene.liu@amd.com>
Cc: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Reviewed-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>