parisc: remove arch/parisc/nm

Parisc overrides 'nm' with a shell script. I was hit by a false-positive
error of $(NM) because this script returns the exit status of grep
instead of ${CROSS_COMPILE}nm. (grep returns 1 if no lines were selected)

I tried to fix it, but in the code review, Helge suggested to remove it
entirely. [1]

This script was added in 2003. [2]

Presumably, it was a workaround for old toolchains (but even the parisc
maintainer does not know the detail any more).

Hopefully, recent tools should work fine.

[1]: https://lore.kernel.org/all/[e-mail]/
[2]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=36eaa6e4c0e0b6950136b956b72fd08155b92ca3

Suggested-by: Helge Deller <[e-mail]>
Signed-off-by: Masahiro Yamada <[e-mail]>
Acked-by: Helge Deller <[e-mail]>

arch/parisc/Makefile

···
 boot := arch/parisc/boot
 KBUILD_IMAGE := $(boot)/bzImage
 
-NM		= sh $(srctree)/arch/parisc/nm
 CHECKFLAGS	+= -D__hppa__=1
 
 ifdef CONFIG_64BIT

arch/parisc/nm

···
-#!/bin/sh
-##
-# Hack to have an nm which removes the local symbols.  We also rely
-# on this nm being hidden out of the ordinarily executable path
-##
-${CROSS_COMPILE}nm $* | grep -v '.LC*[0-9]*$'