phy: broadcom: Kconfig: Add configuration menu for Broadcom phy drivers

Adding a configuration menu to hold many Broadcom phy drivers
helps to make the menu display more concise.

Signed-off-by: Cai Huoqing <caihuoqing@baidu.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20210923025013.189-1-caihuoqing@baidu.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>