lib: rmii-mac mode: bugfix: correction on PLL_1_C register address
lib: rmii-mac mode: bugfix: correction on PLL_1_C register address

* Bug was introduced in commit "66f9792f lib: rewrite rmii clocking setup"
  while manually merging HEAD
  "9513cd13 cgu: configure PLL1 at 50MHz for RMII-MAC mode"
  from branch feature/rmii into master.
* Offsets now line up with Table 81 of UM10944.

Signed-off-by: Tim Scott <d51d62fe9d8cefd758dea882c8aef7b8e2a7b7ec@johndeere.com>
Signed-off-by: Vladimir Oltean <6ef50fec496bca30294ed8eff4f157ee91f2dc55@nxp.com>

openil/sja1105-tool,openil/sja1105-tool