ACPICA: struct acpi_resource_dma: Replace 1-element array with flexible array

ACPICA commit 8409bb869a1790f6e02391c3f0eaf9c5fa63e33f

Similar to "Replace one-element array with flexible-array", replace the
1-element array with a proper flexible array member as defined by C99,
but without changing the structure size.

This allows the code to operate without tripping compile-time and run-
time bounds checkers (e.g. via __builtin_object_size(), -fsanitize=bounds,
and/or -fstrict-flex-arrays=3). As with IRQs, leave a single element in
a union.

No binary changes appear in the .text nor .data sections.

Link: https://github.com/acpica/acpica/commit/8409bb86


Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>