update hdmi driver:
1. rk30 hdmi ddc rate set to 50KHz.
2. flush work quene when hdmi suspend.
3. add irq enable flag to rk30 hdmi.
modify pizza2 defconfig
Merge commit 'c7a92ab6ee0363a79dd8109d1d4dc16f5a457c29' into rockchip-3.0-rbox-kk