stmmac: improve Kconfig help

Signed-off-by: NGiuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/stmmac/Kconfig

@@ -4,8 +4,9 @@ config STMMAC_ETH
 	select PHYLIB
 	depends on NETDEVICES && CPU_SUBTYPE_ST40
 	help
-	  This is the driver for the ST MAC 10/100/1000 on-chip Ethernet
-	  controllers. ST Ethernet IPs are built around a Synopsys IP Core.
+	  This is the driver for the Ethernet IPs are built around a
+	  Synopsys IP Core and fully tested on the STMicroelectronics
+	  platforms.
 
 if STMMAC_ETH
 
@@ -32,7 +33,8 @@ config STMMAC_TIMER
 	default n
 	help
 	  Use an external timer for mitigating the number of network
-	  interrupts.
+	  interrupts. Currently, for SH architectures, it is possible
+	  to use the TMU channel 2 and the SH-RTC device.
 
 choice
         prompt "Select Timer device"