soc/fsl/qbman: Drop set/clear_bits usage

Replace PPC specific set/clear_bits API with standard
bit twiddling so driver is portalable outside PPC.

Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: Roy Pledge <roy.pledge@nxp.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>