ARM: ixp4xx: fix compile-testing soc drivers

Randconfig builds on the ixp4xx ethernet driver showed that the qmgr and
npe drivers are not actually built even when compile testing is enabled:

ERROR: modpost: "qmgr_stat_empty" [drivers/net/ethernet/xscale/ixp4xx_eth.ko] undefined!
ERROR: modpost: "qmgr_enable_irq" [drivers/net/ethernet/xscale/ixp4xx_eth.ko] undefined!
ERROR: modpost: "qmgr_set_irq" [drivers/net/ethernet/xscale/ixp4xx_eth.ko] undefined!
ERROR: modpost: "__qmgr_request_queue" [drivers/net/ethernet/xscale/ixp4xx_eth.ko] undefined!
ERROR: modpost: "npe_send_recv_message" [drivers/net/ethernet/xscale/ixp4xx_eth.ko] undefined!
ERROR: modpost: "npe_recv_message" [drivers/net/ethernet/xscale/ixp4xx_eth.ko] undefined!
ERROR: modpost: "npe_load_firmware" [drivers/net/ethernet/xscale/ixp4xx_eth.ko] undefined!
ERROR: modpost: "npe_running" [drivers/net/ethernet/xscale/ixp4xx_eth.ko] undefined!
ERROR: modpost: "qmgr_disable_irq" [drivers/net/ethernet/xscale/ixp4xx_eth.ko] undefined!
ERROR: modpost: "qmgr_stat_below_low_watermark" [drivers/net/ethernet/xscale/ixp4xx_eth.ko] undefined!

Fix it by always entering the drivers/soc/ixp4xx/ directory, and fix the
resulting compile test failures by removing the #include statements
that prevent building on most other platforms.

Fixes: 7a6c9dbb ("soc: ixp4xx: Protect IXP4xx SoC drivers by ARCH_IXP4XX || COMPILE_TEST")
Fixes: fcf2d897 ("ARM: ixp4xx: Move NPE and QMGR to drivers/soc")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20210721211412.3537004-1-arnd@kernel.org'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

drivers/soc/Makefile

@@ -13,7 +13,7 @@ obj-$(CONFIG_MACH_DOVE)		+= dove/
 obj-y				+= fsl/
 obj-$(CONFIG_ARCH_GEMINI)	+= gemini/
 obj-y				+= imx/
-obj-$(CONFIG_ARCH_IXP4XX)	+= ixp4xx/
+obj-y				+= ixp4xx/
 obj-$(CONFIG_SOC_XWAY)		+= lantiq/
 obj-$(CONFIG_LITEX_SOC_CONTROLLER) += litex/
 obj-y				+= mediatek/

drivers/soc/ixp4xx/ixp4xx-npe.c

@@ -21,7 +21,6 @@
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
 #include <linux/soc/ixp4xx/npe.h>
-#include <mach/hardware.h>
 #include <linux/soc/ixp4xx/cpu.h>
 
 #define DEBUG_MSG			0

drivers/soc/ixp4xx/ixp4xx-qmgr.c

@@ -12,7 +12,6 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/soc/ixp4xx/qmgr.h>
-#include <mach/hardware.h>
 #include <linux/soc/ixp4xx/cpu.h>
 
 static struct qmgr_regs __iomem *qmgr_regs;