Add clickable phone number to main menu

the simple way : – just insert to your main menu a telephone link – you can have there even images before the label text etc.
e.g:
as link: tel:905.639.9972 and f.e. put in as label : [av_font_icon icon='ue854' font='entypo-fontello' size='30px' position='left' color=''][/av_font_icon] Call us
______________
or is it ok for you – if you only have an icon ( telephone ) besides the social media icons?
create a custom social icon:

function avia_add_telephone_icon($icons) {
  $icons['tel']  = array( 'font' =>'entypo-fontello', 'icon' => 'ue854');
  return $icons;
}
add_filter('avf_default_icons','avia_add_telephone_icon', 10, 1);

// Add new icon as an option for social icons
function avia_add_telephone_social_icon($icons) {
  $icons['Tel'] = 'tel';
  return $icons;
}
add_filter('avf_social_icons_options','avia_add_telephone_social_icon', 10, 1);

the new “social media link” will be at the end of the dropdown list in social media symbols enter then your telephone number as link ( tel:905.639.9972 )
maybe better with your country

if you like to have it more perfect – you can style it like every other social media link:

#top #wrap_all .av-social-link-tel:hover a, 
#top #wrap_all .av-social-link-tel a:focus {
  color: #fff;
  background-color: #37589b;
}

etc.