kernelconfig_penguin
is selected by
CONFIG_MICROSEMI_PHY

CONFIG_PTP_1588_CLOCK_OPTIONAL (not configurable)

configname: CONFIG_PTP_1588_CLOCK_OPTIONAL

Linux Kernel Configuration
└─> Device Drivers
└─> PTP clock support
└─> PTP_1588_CLOCK_OPTIONAL

Drivers that can optionally use the PTP_1588_CLOCK framework
should depend on this symbol to prevent them from being built
into vmlinux while the PTP support itself is in a loadable
module.
If PTP support is disabled, this dependency will still be
met, and drivers refer to dummy helpers.