Use a less generic name for IEEE802.11 CRC-32 routine

Use a less generic name for IEEE802.11 CRC-32 routine

Hostapd uses 'crc32' name for IEEE802.11 CRC-32 routine. This name is
too generic. Buildroot autobuilder detected build configuration that
failed to build due to the naming conflict: static linking with openssl
using zlib-ng as a zlib provider, e.g. see:
- http://autobuild.buildroot.net/results/9901df820d3afa4cde78e8ad6d62cb8ce7e69fdb/
- http://autobuild.buildroot.net/results/ac19975f0bf77f4a8ca574c374092ba81cd5a332/

Use a less generic name ieee80211_crc32 for IEEE802.11 CRC-32 routine
to avoid such naming conflicts.

Signed-off-by: Sergey Matyukevich <geomatsi@gmail.com>