vt_buffer: drop console buffer copying optimisations

These two copy to/from VGA memory, however on the Silicon
Motion SMI750 VGA card on a 64-bit system cause console corruption.

This is due to the hw being buggy and not handling a 64-bit transaction
correctly.

We could try and create a 32-bit version of these routines,
but I'm not sure the optimisation is worth much today.

Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1132826

Tested-by: Huawei engineering.
Signed-off-by: Dave Airlie <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Hurley <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

include/linux/vt_buffer.h

···
 #ifndef VT_BUF_HAVE_RW
 #define scr_writew(val, addr) (*(addr) = (val))
 #define scr_readw(addr) (*(addr))
-#define scr_memcpyw(d, s, c) memcpy(d, s, c)
-#define scr_memmovew(d, s, c) memmove(d, s, c)
-#define VT_BUF_HAVE_MEMCPYW
-#define VT_BUF_HAVE_MEMMOVEW
 #endif
 
 #ifndef VT_BUF_HAVE_MEMSETW