pc-bios/optionrom: use -m16 unconditionally

Remove support for .code16gcc, all supported platforms have -m16.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

pc-bios/optionrom/Makefile

@@ -11,7 +11,7 @@ CFLAGS = -O2 -g
 quiet-command = $(if $(V),$1,$(if $(2),@printf "  %-7s %s\n" $2 $3 && $1, @$1))
 cc-option = $(if $(shell $(CC) $1 -c -o /dev/null -xc /dev/null >/dev/null 2>&1 && echo OK), $1, $2)
 
-override CFLAGS += -march=i486 -Wall
+override CFLAGS += -march=i486 -Wall -m16
 
 # If -fcf-protection is enabled in flags or compiler defaults that will
 # conflict with -march=i486
@@ -24,21 +24,8 @@ override CFLAGS += $(filter -W%, $(QEMU_CFLAGS))
 override CFLAGS += $(call cc-option, -fno-pie)
 override CFLAGS += -ffreestanding -I$(TOPSRC_DIR)/include
 override CFLAGS += $(call cc-option, -fno-stack-protector)
-override CFLAGS += $(call cc-option, -m16)
 override CFLAGS += $(call cc-option, -Wno-array-bounds)
 
-ifeq ($(filter -m16, $(CFLAGS)),)
-# Attempt to work around compilers that lack -m16 (GCC <= 4.8, clang <= ??)
-# On GCC we add -fno-toplevel-reorder to keep the order of asm blocks with
-# respect to the rest of the code.  clang does not have -fno-toplevel-reorder,
-# but it places all asm blocks at the beginning and we're relying on it for
-# the option ROM header.  So just force clang not to use the integrated
-# assembler, which doesn't support .code16gcc.
-override CFLAGS += $(call cc-option, -fno-toplevel-reorder)
-override CFLAGS += $(call cc-option, -no-integrated-as)
-override CFLAGS += -m32 -include $(SRC_DIR)/code16gcc.h
-endif
-
 Wa = -Wa,
 override ASFLAGS += -32
 override CFLAGS += $(call cc-option, $(Wa)-32)

pc-bios/optionrom/code16gcc.h

-asm(
-".code16gcc\n"
-);