MIPS: Pistachio: Remove plat_setup_iocoherency

The Pistachio SoC does not have an IOCU.  Hence, DMA is non-coherent.

Remove the function checking for iocoherency and select
CONFIG_DMA_NONCOHERENT in Kconfig

This code is probably accidentally inherited from Malta.
Signed-off-by: NZubair Lutfullah Kakakhel <Zubair.Kakakhel@imgtec.com>
Reviewed-by: NJames Hartley <james.hartley@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/13433/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -384,7 +384,7 @@ config MACH_PISTACHIO
 	select CLKSRC_MIPS_GIC
 	select COMMON_CLK
 	select CSRC_R4K
-	select DMA_MAYBE_COHERENT
+	select DMA_NONCOHERENT
 	select GPIOLIB
 	select IRQ_MIPS_CPU
 	select LIBFDT

arch/mips/pistachio/init.c

@@ -60,29 +60,6 @@ const char *get_system_type(void)
 	return sys_type;
 }
 
-static void __init plat_setup_iocoherency(void)
-{
-	/*
-	 * Kernel has been configured with software coherency
-	 * but we might choose to turn it off and use hardware
-	 * coherency instead.
-	 */
-	if (mips_cm_numiocu() != 0) {
-		/* Nothing special needs to be done to enable coherency */
-		pr_info("CMP IOCU detected\n");
-		hw_coherentio = 1;
-		if (coherentio == 0)
-			pr_info("Hardware DMA cache coherency disabled\n");
-		else
-			pr_info("Hardware DMA cache coherency enabled\n");
-	} else {
-		if (coherentio == 1)
-			pr_info("Hardware DMA cache coherency unsupported, but enabled from command line!\n");
-		else
-			pr_info("Software DMA cache coherency enabled\n");
-	}
-}
-
 void __init *plat_get_fdt(void)
 {
 	if (fw_arg0 != -2)
@@ -93,8 +70,6 @@ void __init *plat_get_fdt(void)
 void __init plat_mem_setup(void)
 {
 	__dt_setup_arch(plat_get_fdt());
-
-	plat_setup_iocoherency();
 }
 
 #define DEFAULT_CPC_BASE_ADDR	0x1bde0000