x86/cyrix: include header linux/isa-dma.h

x86/kernel/cpu/cyrix.c now needs to include <linux/isa-dma.h> since the
'isa_dma_bridge_buggy' variable was moved to it.

Fixes this build error:

  ../arch/x86/kernel/cpu/cyrix.c: In function ‘init_cyrix’:
  ../arch/x86/kernel/cpu/cyrix.c:277:17: error: ‘isa_dma_bridge_buggy’ undeclared (first use in this function)
    277 |                 isa_dma_bridge_buggy = 2;

Fixes: abb4970 ("PCI: Move isa_dma_bridge_buggy out of asm/dma.h")
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Randy Dunlap <[email protected]>
Signed-off-by: Bjorn Helgaas <[email protected]>
Acked-by: Stafford Horne <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: [email protected]

Author: rddunlap

arch/x86/kernel/cpu/cyrix.c

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 #include <linux/bitops.h>
 #include <linux/delay.h>
+#include <linux/isa-dma.h>
 #include <linux/pci.h>
 #include <asm/dma.h>
 #include <linux/io.h>