timer: mchp-pit64b: add support for pit64b

Add support for Microchip PIT64B timer. The timer is 64 bit length and
is used as a free running counter (in continuous mode with highest values
for period registers). The clock feeding the timer would be no more
than 12.5MHz.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
diff --git a/drivers/timer/Kconfig b/drivers/timer/Kconfig
index 6370244..12020e4 100644
--- a/drivers/timer/Kconfig
+++ b/drivers/timer/Kconfig
@@ -213,4 +213,11 @@
 	  Select this to enable support for the timer found on
 	  MediaTek devices.
 
+config MCHP_PIT64B_TIMER
+	bool "Microchip 64-bit periodic interval timer support"
+	depends on TIMER
+	help
+	  Select this to enable support for Microchip 64-bit periodic
+	  interval timer.
+
 endmenu