hw/acpi: extract acpi_add_rom_blob()

hw/acpi: extract acpi_add_rom_blob()

arm and i386 has almost the same function acpi_add_rom_blob(), except
giving different FWCfgCallback function.

This patch moves acpi_add_rom_blob() to utils.c by passing
FWCfgCallback to it.

Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
v7:
  * rebase on top of current master because of conflict
v6:
  * change author from Igor to Michael
v5:
  * remove unnecessary header glib/gprintf.h
  * rearrange include header to make it more suitable
v4:
  * extract -> moves
  * adjust comment in source to make checkpatch happy
v3:
  * put acpi_add_rom_blob() to hw/acpi/utils.c
v2:
  * remove unused header in original source file
Message-Id: <20190610011830.28398-1-richardw.yang@linux.intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>