net: fill in MODULE_DESCRIPTION()s for ocelot

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add descriptions to the Ocelot SoCs (VSC7514) helpers driver.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>