riscv: global_data.h: Correct the comment for PLICSW

PLIC is used for external interrupt, while PLICSW is an Andes-specific
design for software interrupt.

Signed-off-by: Yu Chien Peter Lin <peterlin@andestech.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Reviewed-by: Rick Chen <rick@andestech.com>
diff --git a/arch/riscv/include/asm/global_data.h b/arch/riscv/include/asm/global_data.h
index 6fdc86d..31ba726 100644
--- a/arch/riscv/include/asm/global_data.h
+++ b/arch/riscv/include/asm/global_data.h
@@ -22,7 +22,7 @@
 	void __iomem *clint;	/* clint base address */
 #endif
 #ifdef CONFIG_ANDES_PLICSW
-	void __iomem *plicsw;	/* plic base address */
+	void __iomem *plicsw;	/* andes plicsw base address */
 #endif
 #if CONFIG_IS_ENABLED(SMP)
 	struct ipi_data ipi[CONFIG_NR_CPUS];