kbuild: redo fake deps at include/ksym/*.h

Commit 0e0345b7 ("kbuild: redo fake deps at include/config/*.h")
simplified the Kconfig/fixdep interaction a lot.

For CONFIG_FOO_BAR_BAZ, Kconfig now touches include/config/FOO_BAR_BAZ
instead of the previous include/config/foo/bar/baz.h .

This commit simplifies the TRIM_UNUSED_KSYMS feature in a similar way:

  - delete .h suffix
  - delete tolower()
  - put everything in 1 directory

For EXPORT_SYMBOL(FOO_BAR_BAZ), scripts/adjust_autoksyms.sh now touches
include/ksym/FOO_BAR_BAZ instead of include/ksym/foo/bar/baz.h .

This is more precise, avoiding possibly unnecessary rebuilds.

  EXPORT_SYMBOL(FOO_BAR_BAZ)
  EXPORT_SYMBOL(_FOO_BAR_BAZ)
  EXPORT_SYMBOL(__FOO_BAR_BAZ)

were previously mapped to the same header, include/ksym/foo/bar/baz.h
but now are handled separately.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>

scripts/adjust_autoksyms.sh

@@ -42,10 +42,10 @@ $CONFIG_SHELL $srctree/scripts/gen_autoksyms.sh "$new_ksyms_file"
 changed=$(
 count=0
 sort "$cur_ksyms_file" "$new_ksyms_file" | uniq -u |
-sed -n 's/^#define __KSYM_\(.*\) 1/\1/p' | tr "A-Z_" "a-z/" |
+sed -n 's/^#define __KSYM_\(.*\) 1/\1/p' |
 while read sympath; do
 	if [ -z "$sympath" ]; then continue; fi
-	depfile="include/ksym/${sympath}.h"
+	depfile="include/ksym/${sympath}"
 	mkdir -p "$(dirname "$depfile")"
 	touch "$depfile"
 	# Filesystems with coarse time precision may create timestamps

scripts/gen_ksymdeps.sh

@@ -10,7 +10,7 @@ set -e
 # TODO:
 #   Use -q instead of 2>/dev/null when we upgrade the minimum version of
 #   binutils to 2.37, llvm to 13.0.0.
-ksyms=$($NM $1 2>/dev/null | sed -n 's/.*__ksym_marker_\(.*\)/\1/p' | tr A-Z a-z)
+ksyms=$($NM $1 2>/dev/null | sed -n 's/.*__ksym_marker_\(.*\)/\1/p')
 
 if [ -z "$ksyms" ]; then
 	exit 0
@@ -21,8 +21,7 @@ echo "ksymdeps_$1 := \\"
 
 for s in $ksyms
 do
-	echo $s | sed -e 's:^_*:    $(wildcard include/ksym/:' \
-			-e 's:__*:/:g' -e 's/$/.h) \\/'
+	printf '    $(wildcard include/ksym/%s) \\\n' "$s"
 done
 
 echo