Update .gitignore files for generated targets

The generated 'capflags.c' file wasn't properly ignored, and the list of
files in scripts/basic/ wasn't up-to-date.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/x86/kernel/cpu/.gitignore

+capflags.c

scripts/basic/.gitignore

+hash
 fixdep
-split-include
 docproc