x86/asm: Remove the last GLOBAL user and remove the macro

Convert the remaining 32bit users and remove the GLOBAL macro finally.
In particular, this means to use SYM_ENTRY for the singlestepping hack
region.

Exclude the global definition of GLOBAL from x86 too.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-arch@vger.kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191011115108.12392-20-jslaby@suse.cz