drm/radeon: fix typo in finding PLL params
drm/radeon: fix typo in finding PLL params

Otherwise the limit is raised to high.

Signed-off-by: Christian König <c7ea837d7a46effe4232b086213468b8b31643bf@amd.com>
Tested-by: Ken Moffat <41008776ab4d55ce8185a590654294406e45c249@ntlworld.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs