include/linux/io-mapping.h: remove fallback for writecombine

The fallback was introduced in commit 80c33624e472 ("io-mapping: Fixup
for different names of writecombine") to fix the build on microblaze.

5 years later, it seems all archs now provide a pgprot_writecombine(),
so just remove the other possible fallbacks.  For microblaze,
pgprot_writecombine() is available since commit 97ccedd793ac
("microblaze: Provide pgprot_device/writecombine macros for nommu").

This is build-tested on microblaze with a hack to always build
mm/io-mapping.o and without DIYing on an x86-only macro
(_PAGE_CACHE_MASK)

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Lucas De Marchi <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Daniel Vetter <[email protected]>
Cc: Joonas Lahtinen <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions