ANDROID: fix kernelci compressed kernel linking

Kernel versions 5.4 and below have several bogus relocations defined in
arch/x86/boot/compressed/head_32.S that cause build errors like the
following when linked with the llvm toolchain:

ld.lld: error: relocation R_386_32 cannot be used against symbol '_bss';
recompile with -fPIC

These errors only show up when linking with LLD because BFD allows
relocations in read-only sections by default. Change
ffb6c5f4 ("FROMLIST: x86/boot: allow a relocatable kernel to
be linked with lld") was ported use the same linker flags as ld.bfd for
ld.lld, but guards them with CONFIG_RELOCATABLE. However, the compressed
kernel is built using position-independent code regardless of whether
CONFIG_RELOCATABLE is true or not, causing errors when kernelci builds
i386 with the allnoconfig.

Remove the CONFIG_RELOCATABLE guard around "-z notext" to unblock
kernelci builds for 5.4 branches.

Bug: 430124841

Change-Id: I393174e264fbc0181abb5ecfd518055a7cb14162
Signed-off-by: Tiffany Yang <ynaffit@google.com>