Fix 475MHz min. freq bug

Signed-off-by: Xmister <xmisterhu@gmail.com>
PMC ideal freq. fixed

Signed-off-by: Xmister <xmisterhu@gmail.com>
Fix 475MHz min. freq bug #2

Signed-off-by: Xmister <xmisterhu@gmail.com>
#289

Signed-off-by: Xmister <xmisterhu@gmail.com>