Convert CONFIG_SPL_GPIO_SUPPORT to Kconfig

configs/pcm051_rev1_defconfig

configs/pcm051_rev3_defconfig

configs/pcm058_defconfig

configs/pengwyn_defconfig

configs/pepper_defconfig

configs/picosam9g45_defconfig

configs/platinum_picon_defconfig

configs/platinum_titanium_defconfig

configs/pxm2_defconfig

configs/rastaban_defconfig

configs/rut_defconfig

configs/sama5d2_ptc_nandflash_defconfig

configs/sama5d2_ptc_spiflash_defconfig

configs/sama5d2_xplained_mmc_defconfig

configs/sama5d2_xplained_spiflash_defconfig

configs/sama5d3_xplained_mmc_defconfig

configs/sama5d3_xplained_nandflash_defconfig

configs/sama5d3xek_mmc_defconfig

configs/sama5d3xek_nandflash_defconfig

configs/sama5d3xek_spiflash_defconfig