staging: comedi: COMEDI_NI_LABPC_ISA no longer depends on VIRT_TO_BUS

After migrating ISA DMA support from the "ni_labpc" module to the new
"ni_labpc_isadma" module, the `COMEDI_NI_LABPC_ISA` configuration option
no longer depends on `VIRT_TO_BUS`, so remove the dependency.

(The new `COMEDI_NI_LABPC_ISADMA` option does depend on `VIRT_TO_BUS`
but is not configured manually and is only selected automatically if the
`VIRT_TO_BUS` and `ISA_DMA_API` options are set.)
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/Kconfig

@@ -493,7 +493,6 @@ config COMEDI_NI_LABPC_ISA
 	tristate "NI Lab-PC and compatibles ISA support"
 	select COMEDI_NI_LABPC
 	select COMEDI_NI_LABPC_ISADMA if ISA_DMA_API && VIRT_TO_BUS
-	depends on VIRT_TO_BUS
 	---help---
 	  Enable support for National Instruments Lab-PC and compatibles
 	  Lab-PC-1200, Lab-PC-1200AI, Lab-PC+.