Change in coreboot[master]: drivers/spi: add IS_ENABLED() around Kconfig symbol references

[build bot (Jenkins) (Code Review)]

build bot (Jenkins) has posted comments on this change. ( https://review.coreboot.org/20339 )

Change subject: drivers/spi: add IS_ENABLED() around Kconfig symbol references
......................................................................

Patch Set 2:

Build Successful

https://qa.coreboot.org/job/coreboot-gerrit/56504/ : SUCCESS

https://qa.coreboot.org/job/coreboot-checkpatch/12089/ : SUCCESS