EDID: improved debugging and 2 patches

1.) made some improvements for debugging of EDID, all three levels are configurable via .config:
CONFIG_BASIC_EDID_DEBUG = y
CONFIG_HDMI_EDID_DEBUG = y
CONFIG_HDMI_LCDC_EDID_DEBUG = y

2.) patch the case that the basic EDID block contains the preferred timing (was not used before in case some SVD was also present at the same time)
CONFIG_EDID_BASICTOSVD_GEN2THOMAS_FIX = y

3.) patch unstable and incomplete method to find best mode
CONFIG_EDID_FINDBESTMODE_GEN2THOMAS_FIX = y