riscv: only select DMA_DIRECT_REMAP from RISCV_ISA_ZICBOM and ERRATA_THEAD_PBMT

RISCV_DMA_NONCOHERENT is also used for whacky non-standard
non-coherent ops that use different hooks in dma-direct.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Tested-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20231018052654.50074-3-hch@lst.deSigned-off-by: Geert Uytterhoeven <geert+renesas@glider.be>

arch/riscv/Kconfig

@@ -273,7 +273,6 @@ config RISCV_DMA_NONCOHERENT
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select DMA_BOUNCE_UNALIGNED_KMALLOC if SWIOTLB
-	select DMA_DIRECT_REMAP if MMU
 
 config RISCV_NONSTANDARD_CACHE_OPS
 	bool
@@ -549,6 +548,7 @@ config RISCV_ISA_ZICBOM
 	depends on RISCV_ALTERNATIVE
 	default y
 	select RISCV_DMA_NONCOHERENT
+	select DMA_DIRECT_REMAP
 	help
 	   Adds support to dynamically detect the presence of the ZICBOM
 	   extension (Cache Block Management Operations) and enable its

arch/riscv/Kconfig.errata

@@ -77,6 +77,7 @@ config ERRATA_THEAD_PBMT
 config ERRATA_THEAD_CMO
 	bool "Apply T-Head cache management errata"
 	depends on ERRATA_THEAD && MMU
+	select DMA_DIRECT_REMAP
 	select RISCV_DMA_NONCOHERENT
 	default y
 	help