RISC-V: make ARCH_THEAD preclude XIP_KERNEL

Randy reported build errors in linux-next where XIP_KERNEL was enabled.
ARCH_THEAD requires alternatives to support the non-standard ISA
extensions used by the THEAD cores, which are mutually exclusive with
XIP kernels. Clone the dependency list from the Allwinner entry, since
Allwinner's D1 uses T-Head cores with the same non-standard extensions.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Link: https://lore.kernel.org/all/ab38f6af-cb68-a918-1a63-2e7c927a8ffc@infradead.org/
Fixes: da47ce00 ("riscv: Add the T-HEAD SoC family Kconfig option")
Reviewed-by: Palmer Dabbelt <palmer@rivosinc.com>
Acked-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20230628-left-attractor-94b7bd5fbb83@wendySigned-off-by: Arnd Bergmann <arnd@arndb.de>

arch/riscv/Kconfig.socs

@@ -43,6 +43,7 @@ config ARCH_SUNXI
 
 config ARCH_THEAD
 	bool "T-HEAD RISC-V SoCs"
+	depends on MMU && !XIP_KERNEL
 	select ERRATA_THEAD
 	help
 	  This enables support for the RISC-V based T-HEAD SoCs.