x86 setup: correct the base in the GDT_ENTRY() macro

The GDT_ENTRY() macro in pm.c would incorrectly cut the bottom 8 bits
off the base.  We didn't define any bases with the bottom 8 bits
nonzero, so it is a non-manifest bug, but it's still a bug.

Pointed out by John Smith <johnsmith9344@gmail.com>.
Cc: John Smith <johnsmith9344@gmail.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/boot/pm.c

@@ -104,7 +104,7 @@ static void reset_coprocessor(void)
 	(((u64)(base & 0xff000000) << 32) |	\
 	 ((u64)flags << 40) |			\
 	 ((u64)(limit & 0x00ff0000) << 32) |	\
-	 ((u64)(base & 0x00ffff00) << 16) |	\
+	 ((u64)(base & 0x00ffffff) << 16) |	\
 	 ((u64)(limit & 0x0000ffff)))
 
 struct gdt_ptr {