ALSA: hda - hdmi: Fix wrong baseline length in ATI/AMD generated ELD

According to the HDA specification the baseline ELD length is counted in
DW of 4 bytes instead of in bytes.

Fix the code accordingly.

Baseline length is not used by the kernel so only the ELD exported to
userspace was affected. No issues have been reported.

v2: Fixed so that eld_size is adjusted upwards accordingly as well.

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: Takashi Iwai <tiwai@suse.de>