ARC: uaccess: fix generic 64bit user get operation

Fix get_user macro build error for ARCv3 32bit with disabled
CONFIG_ARC_HAS_LL64 option.
Switch to modifier that is supported by all ARCv1/ARCv2/ARCv3
compilers.

Signed-off-by: Pavel Kozlov <pavel.kozlov@synopsys.com>

Author: pavelvkozlov

arch/arc/include/asm/uaccess.h

@@ -109,15 +109,15 @@
 #define __arc_get_user_one_64(dst, src, ret)	\
 	__asm__ __volatile__(                   \
 	"1:	ld   %1,[%2]\n"			\
-	"4:	ld  %R1,[%2, 4]\n"		\
+	"4:	ld  %H1,[%2, 4]\n"		\
 	"2:	;nop\n"				\
 	"	.section .fixup, \"ax\"\n"	\
 	"	.align 4\n"			\
 	"3:	# return -EFAULT\n"		\
 	"	mov %0, %3\n"			\
 	"	# zero out dst ptr\n"		\
 	"	mov %1,  0\n"			\
-	"	mov %R1, 0\n"			\
+	"	mov %H1, 0\n"			\
 	"	b   2b\n"			\
 	"	.previous\n"			\
 	"	.section __ex_table, \"a\"\n"	\