boards: Remove empty BOARD_SPECIFIC_OPTIONS

While there are currently uses for a stanza of "config BOARD_SPECIFIC_OPTIONS"
followed by "def_bool y" and a series of select/imply statements, having
this option set followed by nothing else doesn't provide anything.
Remove these stanzas.

Signed-off-by: Tom Rini <trini@konsulko.com>

board: rockchip: add Anbernic RGXX3 Series Devices

The Anbernic RGxx3 is a "pseudo-device" that encompasses the following
devices:

- Anbernic RG353M
- Anbernic RG353P
- Anbernic RG353V
- Anbernic RG353VS
- Anbernic RG503

The rk3566-anbernic-rgxx3.dtsi is synced with upstream Linux, but
rk3566-anbernic-rgxx3.dts is a U-Boot specific devicetree that
is used for all RGxx3 devices.

Via the board.c file, the bootloader automatically sets the correct
fdtfile, board, and board_name environment variables so that the
correct devicetree can be passed to Linux. It is also possible to
simply hard-code a single devicetree in the boot.scr file and use
that to load Linux as well.

The common specifications for each device are:

- Rockchip RK3566 SoC
- 2 external SDMMC slots
- 1 USB-C host port, 1 USB-C peripheral port
- 1 mini-HDMI output
- MIPI-DSI based display panel
- ADC controlled joysticks with a GPIO mux
- GPIO buttons
- A PWM controlled vibrator
- An ADC controlled button

All of the common features are defined in the devicetree synced from
upstream Linux.

TODO: DSI panel auto-detection for the RG353 devices (requires porting
of DSI controller driver and DSI-DPHY driver to send DSI commands to
the panel).

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

board: rockchip: add Anbernic RGXX3 Series Devices

The Anbernic RGxx3 is a "pseudo-device" that encompasses the following
devices:

- Anbernic RG353M
- Anbernic RG353P
- Anbernic RG353V
- Anbernic RG353VS
- Anbernic RG503

The rk3566-anbernic-rgxx3.dtsi is synced with upstream Linux, but
rk3566-anbernic-rgxx3.dts is a U-Boot specific devicetree that
is used for all RGxx3 devices.

Via the board.c file, the bootloader automatically sets the correct
fdtfile, board, and board_name environment variables so that the
correct devicetree can be passed to Linux. It is also possible to
simply hard-code a single devicetree in the boot.scr file and use
that to load Linux as well.

The common specifications for each device are:

- Rockchip RK3566 SoC
- 2 external SDMMC slots
- 1 USB-C host port, 1 USB-C peripheral port
- 1 mini-HDMI output
- MIPI-DSI based display panel
- ADC controlled joysticks with a GPIO mux
- GPIO buttons
- A PWM controlled vibrator
- An ADC controlled button

All of the common features are defined in the devicetree synced from
upstream Linux.

TODO: DSI panel auto-detection for the RG353 devices (requires porting
of DSI controller driver and DSI-DPHY driver to send DSI commands to
the panel).

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>