arm64: dts: ti: k3-am62x-sk-common: Improve documentation of mcasp1_pins

Include documentation of the AMC package pin name as well to keep it
consistent with the rest of the pinctrl documentation.

Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20230418213740.153519-5-nm@ti.com


Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>