staging: fsl-mc: fix formating of phys_addr_t on 32 bits
Use correct format specifier for phys_addr_t variables (%pa) instead
of %llx. This fixes these warnings on 32 bit targets:
"format '%llx' expects argument of type 'long long unsigned int',
but argument 4 has type 'phys_addr_t' [-Wformat=]"