imx8mn-var-som: add manufacturer to target description

Add Variscite manufacturer to the IMX8MN_VAR_SOM target menu label as
the majority of targets include the manufacturer as part of their menu
description/label and it helps when looking for a particular
manufacturer/board.

Signed-off-by: Hugo Villeneuve <hvilleneuve@dimonoff.com>
Reviewed-by: Fabio Estevam <festevam@gmail.com>
diff --git a/arch/arm/mach-imx/imx8m/Kconfig b/arch/arm/mach-imx/imx8m/Kconfig
index b802d5c..67da198 100644
--- a/arch/arm/mach-imx/imx8m/Kconfig
+++ b/arch/arm/mach-imx/imx8m/Kconfig
@@ -256,7 +256,7 @@
 	select IMX8M_LPDDR4
 
 config TARGET_IMX8MN_VAR_SOM
-	bool "imx8mn_var_som"
+	bool "Variscite imx8mn_var_som"
 	select BINMAN
 	select IMX8MN
 	select SUPPORT_SPL