arm/gnttab: Remove xen/grant_table.h cyclic include

The way they currently include each other, with one of the includes
being conditional on CONFIG_GRANT_TABLE, makes it hard to know which
contents are included when.

Break the cycle by removing the asm/grant_table.h include.

Not a functional change because.

Signed-off-by: Alejandro Vallejo <agarciav@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>

xen/arch/arm/include/asm/grant_table.h

@@ -1,7 +1,6 @@
 #ifndef __ASM_GRANT_TABLE_H__
 #define __ASM_GRANT_TABLE_H__
 
-#include <xen/grant_table.h>
 #include <xen/kernel.h>
 #include <xen/pfn.h>
 #include <xen/sched.h>