arch/x86: Remove more romcc leftovers

The sections .rom.* were for romcc and no longer used.
Some romcc comments were left behind when guards were removed.

Change-Id: I060ad7af2f03c67946f9796e625c072b887280c1
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/37955
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/arch/x86/bootblock_crt0.S

@@ -10,11 +10,12 @@
 
 #include <cpu/x86/cr.h>
 
+.section .text
+
 /*
  * Include the old code for reset vector and protected mode entry. That code has
  * withstood the test of time.
  */
-#include <arch/x86/prologue.inc>
 #include <cpu/x86/16bit/entry16.inc>
 #include <cpu/x86/16bit/reset16.inc>
 #include <cpu/x86/32bit/entry32.inc>

src/arch/x86/prologue.inc

@@ -1,6 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-
-#include <cpu/x86/post_code.h>
-
-.section ".rom.data", "a", @progbits
-.section ".rom.text", "ax", @progbits