net: ipa: add config dependency on QCOM_SMEM

The IPA driver depends on some SMEM functionality (qcom_smem_init(),
qcom_smem_alloc(), and qcom_smem_virt_to_phys()), but this is not
reflected in the configuration dependencies.  Add a dependency on
QCOM_SMEM to avoid attempts to build the IPA driver without SMEM.
This avoids a link error for certain configurations.
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: 38a4066f ("net: ipa: support COMPILE_TEST")
Signed-off-by: Alex Elder <elder@linaro.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210112192134.493-1-elder@linaro.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ipa/Kconfig

 config QCOM_IPA
 	tristate "Qualcomm IPA support"
-	depends on 64BIT && NET
+	depends on 64BIT && NET && QCOM_SMEM
 	depends on ARCH_QCOM || COMPILE_TEST
 	depends on QCOM_RPROC_COMMON || (QCOM_RPROC_COMMON=n && COMPILE_TEST)
 	select QCOM_MDT_LOADER if ARCH_QCOM