ARM: at91/trivial: update Kconfig comment to mention SAMA5

Cortex-A5 SAMA5 processors were not listed, add this in the AT91 comment.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Boris BREZILLON <boris.brezillon@free-electrons.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 28f3205..92dbde8 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -380,7 +380,7 @@
 	select USE_OF
 	help
 	  This enables support for systems based on Atmel
-	  AT91RM9200 and AT91SAM9* processors.
+	  AT91RM9200, AT91SAM9 and SAMA5 processors.
 
 config ARCH_CLPS711X
 	bool "Cirrus Logic CLPS711x/EP721x/EP731x-based"