MIPS: BCM63XX: bcm963xx_tag.h: make crc fields integers

All CRC32 fields are 32 bit integers, so define them as such to prevent
unnecessary casts if we want to use them.

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>