The code reading the register does not match the code writing to the register,
fix it.

Also fix the coding style in mc_writel() for better readability.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NStephen Warren <swarren@nvidia.com>
Tested-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>