x86/ACPI/sleep: Move acpi_wakeup_address() definition into sleep.c, remove...

x86/ACPI/sleep: Move acpi_wakeup_address() definition into sleep.c, remove <asm/realmode.h> from <asm/acpi.h>

Move the definition of acpi_wakeup_address() into sleep.c to break
linux/acpi.h's dependency (by way of asm/acpi.h) on asm/realmode.h.
Everyone and their mother includes linux/acpi.h, i.e. modifying
realmode.h results in a full kernel rebuild, which makes the already
inscrutable real mode boot code even more difficult to understand and is
positively rage inducing when trying to make changes to x86's boot flow.

[ mingo: Renamed acpi_wakeup_address() to acpi_get_wakeup_address(), as suggested by Borislav Petkov. ]

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20191119002121.4107-13-sean.j.christopherson@intel.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>