[PATCH] soc/fsl/qe: fix usb.c build errors

[Randy Dunlap]

Fix build errors in soc/fsl/qe/usb.c when QUICC_ENGINE is not set.
This happens when PPC_EP88XC is set, which selects CPM1 & CPM.
When CPM is set, USB_FSL_QE can be set without QUICC_ENGINE
being set. When USB_FSL_QE is set, QE_USB deafults to y, which
causes build errors when QUICC_ENGINE is not set. Making
QE_USB depend on QUICC_ENGINE prevents QE_USB from defaulting to y.

Fixes these build errors:

drivers/soc/fsl/qe/usb.o: in function `qe_usb_clock_set':
usb.c:(.text+0x1e): undefined reference to `qe_immr'
powerpc-linux-ld: usb.c:(.text+0x2a): undefined reference to `qe_immr'
powerpc-linux-ld: usb.c:(.text+0xbc): undefined reference to `qe_setbrg'
powerpc-linux-ld: usb.c:(.text+0xca): undefined reference to `cmxgcr_lock'
powerpc-linux-ld: usb.c:(.text+0xce): undefined reference to `cmxgcr_lock'

Fixes: 5e41486c408e ("powerpc/QE: add support for QE USB clocks routing")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Link: https://lore.kernel.org/all/202301101500.pillNv6R-lkp@xxxxxxxxx/
Suggested-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Cc: Leo Li <leoyang.li@xxxxxxx>
Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: Nicolas Schier <nicolas@xxxxxxxxx>
Cc: Qiang Zhao <qiang.zhao@xxxxxxx>
Cc: linuxppc-dev <linuxppc-dev@xxxxxxxxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: Anton Vorontsov <avorontsov@xxxxxxxxxxxxx>
Cc: Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>
---
 drivers/soc/fsl/qe/Kconfig |    1 +
 1 file changed, 1 insertion(+)

diff -- a/drivers/soc/fsl/qe/Kconfig b/drivers/soc/fsl/qe/Kconfig
--- a/drivers/soc/fsl/qe/Kconfig
+++ b/drivers/soc/fsl/qe/Kconfig
@@ -39,6 +39,7 @@ config QE_TDM
 
 config QE_USB
 	bool
+	depends on QUICC_ENGINE
 	default y if USB_FSL_QE
 	help
 	  QE USB Controller support