Convert CONFIG_SYS_TIMER_COUNTS_DOWN to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_TIMER_COUNTS_DOWN

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/socfpga_is1_defconfig b/configs/socfpga_is1_defconfig
index 3a21bc7..32d7b74 100644
--- a/configs/socfpga_is1_defconfig
+++ b/configs/socfpga_is1_defconfig
@@ -69,3 +69,4 @@
 CONFIG_SPI=y
 CONFIG_CADENCE_QSPI=y
 # CONFIG_SPL_WDT is not set
+CONFIG_SYS_TIMER_COUNTS_DOWN=y