update linux-headers to 4.19.88-1

the new release adds support for m68k and s390x archs.

Makefile

@@ -8,7 +8,7 @@ MUSL_VER = 1.2.2
 GMP_VER = 6.1.2
 MPC_VER = 1.1.0
 MPFR_VER = 4.0.2
-LINUX_VER = headers-4.19.88
+LINUX_VER = headers-4.19.88-1
 
 GNU_SITE = https://ftpmirror.gnu.org/gnu
 GCC_SITE = $(GNU_SITE)/gcc

hashes/linux-headers-4.19.88-1.tar.xz.sha1

@@ -0,0 +1 @@
+b35ef708c60381a566f6310a5abcb7a8f149db0d  linux-headers-4.19.88-1.tar.xz