Staging: bcm: Remove typedef for IPV6HeaderFormatTag and call directly.

This patch removes typedef IPV6HeaderFormatTag,
and changes the name of the struct to bcm_ipv6_hdr.
In addition, any calls to typedef IPV6Header
are changed to call the struct directly.

Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>