[PATCH] docs: kernel-parameters: mark numa=off is supported by a bundle of architectures

risc-v and arm64 support numa=off by common arch_numa_init()
in drivers/base/arch_numa.c. x86, ppc, mips, sparc support it
by arch-level early_param.
numa=off is widely used in linux distributions. it is better
to document it.

Signed-off-by: Barry Song <redacted>
---
 Documentation/admin-guide/kernel-parameters.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index cb89dbdedc46..a388fbdaa2ec 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt

@@ -3513,6 +3513,9 @@

 	nr_uarts=	[SERIAL] maximum number of UARTs to be registered.

+	numa=off 	[KNL, ARM64, PPC, RISCV, SPARC, X86] Disable NUMA, Only
+			set up a single NUMA node spanning all memory.
+
 	numa_balancing=	[KNL,ARM64,PPC,RISCV,S390,X86] Enable or disable automatic
 			NUMA balancing.
 			Allowed values are enable and disable