arch: mach-k3: Update board specific API name to K3 generic API name

Although the board_init_f API initialises the SoC, the API name is
incorrectly specified and misleads the functionality. This file should
only include k3-specific functionality. Change the API's name to something
more K3-specific and separate the function to make it more modular.

Signed-off-by: Sinthu Raja <sinthu.raja@ti.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
2 files changed