timer: Add _TIMER suffix to Andes PLMT Kconfig

This matches the naming scheme of other timer drivers.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Rick Chen <rick@andestech.com>
diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig
index 6b8e4c9..80743a2 100644
--- a/drivers/timer/Kconfig
+++ b/drivers/timer/Kconfig
@@ -53,7 +53,7 @@
 	  Select this to enable a timer for Altera devices. Please find
 	  details on the "Embedded Peripherals IP User Guide" of Altera.
 
-config ANDES_PLMT
+config ANDES_PLMT_TIMER
 	bool
 	depends on RISCV_MMODE || SPL_RISCV_MMODE
 	help