There is new permission model in use by apache 2, hence do the following,
<Directory "/usr/share/phpmyadmin">
#Order Deny,Allow
#Deny from all
Options All
AllowOverride All
Require all granted
</Directory>
<Directory "/usr/share/phpmyadmin">
#Order Deny,Allow
#Deny from all
Options All
AllowOverride All
Require all granted
</Directory>