bnx2x: add a separate GENEVE Kconfig symbol

When CONFIG_GENEVE is built as a loadable module, and bnx2x is built-in,
we get this link error:

drivers/net/built-in.o: In function `bnx2x_open':
:(.text+0x33322): undefined reference to `geneve_get_rx_port'
drivers/net/built-in.o: In function `bnx2x_sp_rtnl_task':
:(.text+0x3e632): undefined reference to `geneve_get_rx_port'

This avoids the problem by adding a separate Kconfig symbol named
CONFIG_BNX2X_GENEVE that is only enabled when the code is
reachable from the driver.

This is the same trick that BNX2X does for VXLAN support, and
is similar to how I40E handles both.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 883ce97d

 ("bnx2x: Add Geneve inner-RSS support")
Acked-By: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>