BCM4401 is Ethernet, it should be supported by
bfe(4) or
bce(4).
All the documents I can find for the "Inspiron 5150" show no integrated Wireless chipset at all.. perhaps you have a MiniPCI or PCMCIA card?
You won't truly know if things will work or not until you actually try installing and booting FreeBSD, or at least provide us with a little more info.
Hope that helps.