[PATCH] net: ti: icssg-prueth: add dependency for PTP

[Randy Dunlap]

When CONFIG_PTP_1588_CLOCK=m and CONFIG_TI_ICSSG_PRUETH=y, there are
kconfig dependency warnings and build errors referencing PTP functions.

Fix these by making TI_ICSSG_PRUETH depend on PTP_1588_CLOCK_OPTIONAL.

Fixes these build errors and warnings:

WARNING: unmet direct dependencies detected for TI_ICSS_IEP
  Depends on [m]: NETDEVICES [=y] && ETHERNET [=y] && NET_VENDOR_TI [=y] && PTP_1588_CLOCK_OPTIONAL [=m] && TI_PRUSS [=y]
  Selected by [y]:
  - TI_ICSSG_PRUETH [=y] && NETDEVICES [=y] && ETHERNET [=y] && NET_VENDOR_TI [=y] && PRU_REMOTEPROC [=y] && ARCH_K3 [=y] && OF [=y] && TI_K3_UDMA_GLUE_LAYER [=y]

aarch64-linux-ld: drivers/net/ethernet/ti/icssg/icss_iep.o: in function `icss_iep_get_ptp_clock_idx':
icss_iep.c:(.text+0x1d4): undefined reference to `ptp_clock_index'
aarch64-linux-ld: drivers/net/ethernet/ti/icssg/icss_iep.o: in function `icss_iep_exit':
icss_iep.c:(.text+0xde8): undefined reference to `ptp_clock_unregister'
aarch64-linux-ld: drivers/net/ethernet/ti/icssg/icss_iep.o: in function `icss_iep_init':
icss_iep.c:(.text+0x176c): undefined reference to `ptp_clock_register'

Fixes: 186734c15886 ("net: ti: icssg-prueth: add packet timestamping and ptp support")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Roger Quadros <rogerq@xxxxxx>
Cc: Md Danish Anwar <danishanwar@xxxxxx>
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Reviewed-by: MD Danish Anwar <danishanwar@xxxxxx>
---
v2: removed Rev-by: from Roger Quadros (patch has changed)
    added Rev-by: from MD Danish Anwar

 drivers/net/ethernet/ti/Kconfig |    1 +
 1 file changed, 1 insertion(+)

diff -- a/drivers/net/ethernet/ti/Kconfig b/drivers/net/ethernet/ti/Kconfig
--- a/drivers/net/ethernet/ti/Kconfig
+++ b/drivers/net/ethernet/ti/Kconfig
@@ -189,6 +189,7 @@ config TI_ICSSG_PRUETH
 	select TI_K3_CPPI_DESC_POOL
 	depends on PRU_REMOTEPROC
 	depends on ARCH_K3 && OF && TI_K3_UDMA_GLUE_LAYER
+	depends on PTP_1588_CLOCK_OPTIONAL
 	help
 	  Support dual Gigabit Ethernet ports over the ICSSG PRU Subsystem.
 	  This subsystem is available starting with the AM65 platform.