Staging: bcm: Replace __attribute__((packed)) with __packed in Ioctl.h

This patch fixes the following warning as
reported by checkpath.pl, "WARNING:__packed
is preferred over __attribute__((packed))".

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