Commit a314520d82317650 ("arm64: disable Broadcom Vulcan platform")
did not remove the ARCH_VULCAN configuration symbol, as there were still
references to this symbol.
As of commits 240d3d5b2a7a3263 ("gpio: xlp: update GPIO_XLP dependency") and f85a543e5373eeba ("arm64: defconfig: drop ARCH_VULCAN"), the last users
of ARCH_VULCAN have been removed.