rockchip: rk3588-toybrick: Use pinctrl and aliases in SPL

Pinctrl must be configured for eMMC, SD-card and SPI flash to
successfully read FIT from all possible fallback media in SPL.

Include pinctrl props and enable the SPL_PINCTRL Kconfig option to
ensure FIT can be loaded from eMMC, SD-card and SPI flash.

Also enable the SPL_DM_SEQ_ALIAS Kconfig option to ensure that the
storage device sequence number matches in both SPL and U-Boot proper.

Fixes: 9fdd9a54 ("board: rockchip: add Rockchip Toybrick TB-RK3588X board")
Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>