counter: ftm-quaddec: Depend on the Layerscape SoC

At the moment only the Freescale LS1021A is the only HW that
supports this IP block so add an appropriate dependency and
compile test.
Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Link: https://lore.kernel.org/r/20230108074750.443705-3-pbrobinson@gmail.com/Signed-off-by: William Breathitt Gray <william.gray@linaro.org>

drivers/counter/Kconfig

@@ -31,6 +31,7 @@ config 104_QUAD_8
 
 config FTM_QUADDEC
 	tristate "Flex Timer Module Quadrature decoder driver"
+	depends on SOC_LS1021A || COMPILE_TEST
 	depends on HAS_IOMEM && OF
 	help
 	  Select this option to enable the Flex Timer Quadrature decoder