Remove CONFIG_SPL_PINCTRL_SUPPORT

This option is not used. Drop it.
Signed-off-by: NSimon Glass <sjg@chromium.org>

include/configs/rk3288_common.h

@@ -63,8 +63,6 @@
 #define CONFIG_SYS_MMCSD_FS_BOOT_PARTITION	1
 #define CONFIG_SPL_FS_LOAD_PAYLOAD_NAME		"u-boot.img"
 
-#define CONFIG_SPL_PINCTRL_SUPPORT
-
 #define CONFIG_SYS_SDRAM_BASE		0
 #define CONFIG_NR_DRAM_BANKS		1
 #define SDRAM_BANK_SIZE			(2UL << 30)