Use PPC_FEATURE2_ISEL and PPC_FEATURE2_VEC_CRYPTO from linux headers
instead of the GNU specific PPC_FEATURE2_HAS_ISEL and
PPC_FEATURE2_HAS_VEC_CRYPTO. This fixes build with musl libc.

Cc: qemu-stable@nongnu.org
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1861


Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Fixes: 63922f46 ("tcg/ppc: Replace HAVE_ISEL macro with a variable")
Fixes: 68f340d4 ("tcg/ppc: Enable Altivec detection")
Message-Id: <20231219105236.7059-1-ncopa@alpinelinux.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
(cherry picked from commit 1d513e06d96697f44de4a1b85c6ff627c443e306)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>