realtek: fix "help" line in Kconfig in files/patches for 5.10

realtek: fix "help" line in Kconfig in files/patches for 5.10

In Kernel 5.10, "help" must be used instead of "---help---".

this patch fixes the following errors:

drivers/net/dsa/rtl83xx/Kconfig:7: syntax errorgit
drivers/net/dsa/rtl83xx/Kconfig:6: unknown statement "---help---"
drivers/net/dsa/rtl83xx/Kconfig:7:warning: ignoring unsupported character '.'
drivers/net/dsa/rtl83xx/Kconfig:7: unknown statement "This"
drivers/net/ethernet/Kconfig:170: syntax error
drivers/net/ethernet/Kconfig:169: unknown statement "---help---"
drivers/net/ethernet/Kconfig:170:warning: ignoring unsupported character '.'
drivers/net/ethernet/Kconfig:170: unknown statement "Say"
drivers/net/phy/Kconfig:331: syntax error
drivers/net/phy/Kconfig:330: unknown statement "---help---"
drivers/net/phy/Kconfig:331: unknown statement "Supports"

Signed-off-by: INAGAKI Hiroshi <musashino.open@gmail.com>