arm64: dts: ti: k3-j721s2: Add general purpose timers

arm64: dts: ti: k3-j721s2: Add general purpose timers

There are 20 general purpose timers on j721s2 that can be used for
things like PWM using pwm-omap-dmtimer driver. There are also
additional ten timers in the MCU domain which are meant for MCU
firmware usage and hence marked reserved by default.

Though the count is similar to J721e/J7200, the device IDs and clocks
used in j721s2 are different with the option of certain clocks having
options of additional clock muxes. Since there is very minimal reuse,
it is cleaner to integrate as part of SoC files itself. The defaults
are configured for clocking the timers from system clock(HFOSC0).

Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230531213215.602395-4-nm@ti.com
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>