net: phy: remove kernel-doc duplication

net: phy: remove kernel-doc duplication

Sphinx 3 now checks for duplicated function declarations:

	.../Documentation/networking/kapi:143: ../include/linux/phy.h:163: WARNING: Duplicate C declaration, also defined in 'networking/kapi'.
	Declaration is 'unsigned int phy_supported_speeds (struct phy_device *phy, unsigned int *speeds, unsigned int size)'.
	.../Documentation/networking/kapi:143: ../include/linux/phy.h:1034: WARNING: Duplicate C declaration, also defined in 'networking/kapi'.
	Declaration is 'int phy_read_mmd (struct phy_device *phydev, int devad, u32 regnum)'.
	.../Documentation/networking/kapi:143: ../include/linux/phy.h:1076: WARNING: Duplicate C declaration, also defined in 'networking/kapi'.
	Declaration is 'int __phy_read_mmd (struct phy_device *phydev, int devad, u32 regnum)'.
	.../Documentation/networking/kapi:143: ../include/linux/phy.h:1088: WARNING: Duplicate C declaration, also defined in 'networking/kapi'.
	Declaration is 'int phy_write_mmd (struct phy_device *phydev, int devad, u32 regnum, u16 val)'.
	.../Documentation/networking/kapi:143: ../include/linux/phy.h:1100: WARNING: Duplicate C declaration, also defined in 'networking/kapi'.
	Declaration is 'int __phy_write_mmd (struct phy_device *phydev, int devad, u32 regnum, u16 val)'.

It turns that both the C and the H files have the same
kernel-doc markup for the same functions. Let's drop the
at the header file, keeping the one closer to the code.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/75e9a357f9a716833d2094b04898754876365e68.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>