phy: ti: gmii-sel: fix mac tx internal delay for rgmii-rxid

Now phy-gmii-sel will disable MAC TX internal delay for PHY interface mode
"rgmii-rxid" which is incorrect.
Hence, fix it by enabling MAC TX internal delay in the case of "rgmii-rxid"
mode.

Fixes: 92b58b34

 ("phy: ti: introduce phy-gmii-sel driver")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>