arm64: dts: ti: k3-am62: Add general purpose timers for am62

There are 8 general purpose timers on am65 that can be used for things
like PWM using pwm-omap-dmtimer driver. There are also additional four
timers in the MCU domain that do not have interrupts routable for Linux.

We configure the timers with the 25 MHz input clock by default as the
32.768 kHz clock may not be wired on the device. We leave the MCU domain
timers clock mux unconfigured, and mark the MCU domain timers reserved.
The MCU domain timers are likely reserved by the software for the ESM
module.

Compared to am65, the timers on am62 do not have a dedicated IO mux for
the timers. On am62, the timers have different interrupts, clocks and
power domains compared to am65, and the MCU timers are at a different
IO address.

Cc: Keerthy <j-keerthy@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Georgi Vlaev <g-vlaev@ti.com>
Link: https://lore.kernel.org/r/20221115154842.7755-4-tony@atomide.com