zink: only clear the aspects mentioned in the clear.

This fixes:
dEQP-GLES2.functional.depth_stencil_clear.depth_stencil_scissored

The code was clearing both depth and stencil for clears that were
depth or stencil only.
39 jobs for !9355 with zink-fix-ds-clear in 9 seconds (queued for 2 seconds)
latest detached
Status Job ID Name Coverage
  Sanity
passed #7677597
sanity

00:00:09

 
  Container
manual #7677600
aarch64 manual
arm_build
manual #7677601
manual
arm_test-base
manual #7677602
windows shell 1809 mesa manual
windows_build_vs2019
manual #7677598
manual
x86_build-base
manual #7677599
manual
x86_test-base
 
  Container 2
created #7677610
android_build
created #7677613
arm64_test
created #7677614
armhf_test
created #7677607
i386_build
created #7677603
kernel+rootfs_amd64
created #7677604
aarch64
kernel+rootfs_arm64
created #7677605
aarch64
kernel+rootfs_armhf
created #7677608
ppc64el_build
created #7677609
s390x_build
created #7677606
x86_build
created #7677611
x86_test-gl
created #7677612
x86_test-vk
 
  Meson X86 64
created #7677620
meson-clang
created #7677621
meson-clover
created #7677617
meson-clover-testing
created #7677618
gstreamer
meson-gallium
created #7677619
meson-release
created #7677615
meson-testing
created #7677616
meson-testing-asan
created #7677622
meson-vulkan
 
  Build Misc
created #7677623
meson-android
created #7677625
aarch64
meson-arm64
created #7677626
aarch64
meson-arm64-asan
created #7677627
aarch64
meson-arm64-build-test
created #7677624
aarch64
meson-armhf
created #7677628
meson-i386
created #7677631
meson-mingw32-x86_64
created #7677630
kvm
meson-ppc64el
created #7677629
kvm
meson-s390x
 
  Layered Backends
created #7677635
zink-lvp-gl
created #7677633
zink-lvp-gles2
created #7677634
zink-lvp-gles3
created #7677632
zink-piglit-quick_gl