serial: 8250: split out legacy isa driver
The 8250_platform.c file still contains two completely unrelated drivers:
the early_serial_setup() support used by legacy ISA devices and a small
number of non-x86 machines, and the actual "serial8250" platform_device
driver used by a slightly larger number of other embedded machines
along with the RISC-V ACPI support.
Separate the two by moving out everything that is not needed by the
platform driver into a new 8250_isa.c file, and make both portions
of the driver optional at compile time, with a Kconfig dependency that
only turns these on for platforms that actually use them.
The initialization of the console driver now gets moved back into
the 8250_core.c file to make it still work when the ISA driver is
left out.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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This should probably be split up a little further
6 files changed
