efi/arm: Pass start and end addresses to cache_clean_flush()

In preparation for turning the decompressor's cache clean/flush
operations into proper by-VA maintenance for v7 cores, pass the
start and end addresses of the regions that need cache maintenance
into cache_clean_flush in registers r0 and r1.

Currently, all implementations of cache_clean_flush ignore these
values, so no functional change is expected as a result of this
patch.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

arch/arm/boot/compressed/head.S

@@ -1460,6 +1460,12 @@ ENTRY(efi_stub_entry)
 
 		@ Preserve return value of efi_entry() in r4
 		mov	r4, r0
+		add	r1, r4, #SZ_2M			@ DT end
+		bl	cache_clean_flush
+
+		ldr	r0, [sp]			@ relocated zImage
+		ldr	r1, =_edata			@ size of zImage
+		add	r1, r1, r0			@ end of zImage
 		bl	cache_clean_flush
 
 		@ The PE/COFF loader might not have cleaned the code we are