net: cs89x0: disable compile testing on powerpc

The ISA DMA API is inconsistent between architectures, and while
powerpc implements most of what the others have, it does not provide
isa_virt_to_bus():

../drivers/net/ethernet/cirrus/cs89x0.c: In function ‘net_open’:
../drivers/net/ethernet/cirrus/cs89x0.c:897:20: error: implicit declaration of function ‘isa_virt_to_bus’ [-Werror=implicit-function-declaration]
     (unsigned long)isa_virt_to_bus(lp->dma_buff));
../drivers/net/ethernet/cirrus/cs89x0.c:894:3: note: in expansion of macro ‘cs89_dbg’
   cs89_dbg(1, debug, "%s: dma %lx %lx\n",

I tried a couple of approaches to handle this consistently across
all architectures, but as this driver is really only used on
ARM, I ended up taking the easy way out and just disable compile
testing on powerpc.
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Reported-by: kernel test robot <lkp@intel.com>
Fixes: 47fd22f2 ("cs89x0: rework driver configuration")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/cirrus/Kconfig

@@ -38,7 +38,7 @@ config CS89x0_ISA
 
 config CS89x0_PLATFORM
 	tristate "CS89x0 platform driver support"
-	depends on ARM || COMPILE_TEST
+	depends on ARM || (COMPILE_TEST && !PPC)
 	select CS89x0
 	help
 	  Say Y to compile the cs89x0 platform driver. This makes this driver