microblaze: Kernel parameters should be parsed earlier

Kernel command line should be parsed before cma initialization to be able
to get cma sizes from command line. That's why call parse_early_param()
before dma_continugous_reserve().

Unfortunately it can't be called earlier in machine_early_init() because
if earlycon is passed in the command line the parse_early_param() attempts
an ioremap which fails as the memory params are not set yet.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>