qed: select ZLIB_INFLATE

The newly added qlogic qed driver uses the zlib library, but
misses the dependency:

drivers/built-in.o: In function `qed_alloc_stream_mem':
drivers/net/ethernet/qlogic/qed/qed_main.c:707: undefined reference to `zlib_inflate_workspacesize'
drivers/built-in.o: In function `qed_unzip_data':
drivers/net/ethernet/qlogic/qed/qed_main.c:675: undefined reference to `zlib_inflateInit2'

This changes Kconfig to always select zlib when needed.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: fe56b9e6 ("qed: Add module with basic common support")
Signed-off-by: David S. Miller <davem@davemloft.net>