Implement a clock control driver for Microchip MEC172x handling
configuring the 32 KHz input sources for the PLL and peripheral-32k
clock domains. MEC172x differs from MEC152x. MEC152x had one 32K source
for both PLL and peripherals. MEC172x allows the two domains to use
independent 32 KHz sources. Device tree updated to provide addresses
of hardware used by the driver.
Signed-off-by: Scott Worley <scott.worley@microchip.com>
Added minimal device tree and board files to build Microchip
MEC172x. SOC layer stripped down to allow build for checking
compilation only.
Signed-off-by: Scott Worley <scott.worley@microchip.com>