arm64: KVM: Kill HYP_PAGE_OFFSET

HYP_PAGE_OFFSET is not massively useful. And the way we use it
in KERN_HYP_VA is inconsistent with the equivalent operation in
EL2, where we use a mask instead.

Let's replace the uses of HYP_PAGE_OFFSET with HYP_PAGE_OFFSET_MASK,
and get rid of the pointless macro.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arch/arm64/include/asm/kvm_mmu.h

@@ -70,7 +70,6 @@
  */
 #define HYP_PAGE_OFFSET_SHIFT	VA_BITS
 #define HYP_PAGE_OFFSET_MASK	((UL(1) << HYP_PAGE_OFFSET_SHIFT) - 1)
-#define HYP_PAGE_OFFSET		(PAGE_OFFSET & HYP_PAGE_OFFSET_MASK)
 
 /*
  * Our virtual mapping for the idmap-ed MMU-enable code. Must be
@@ -104,7 +103,7 @@ alternative_endif
 #include <asm/mmu_context.h>
 #include <asm/pgtable.h>
 
-#define KERN_TO_HYP(kva)	((unsigned long)kva - PAGE_OFFSET + HYP_PAGE_OFFSET)
+#define KERN_TO_HYP(kva)	((unsigned long)kva & HYP_PAGE_OFFSET_MASK)
 
 /*
  * We currently only support a 40bit IPA.