vulkan: implement ABS and NEG (#17245)

* docs: update Vulkan ops

* vulkan: add NEG op

* vulkan: add ABS op

---------

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

ggml/src/ggml-vulkan/vulkan-shaders/neg.comp

@@ -0,0 +1,20 @@
+#version 450
+
+#include "generic_head.glsl"
+#include "types.glsl"
+
+#extension GL_EXT_control_flow_attributes : enable
+
+layout(local_size_x = 512, local_size_y = 1, local_size_z = 1) in;
+
+layout (binding = 0) readonly buffer X {A_TYPE data_a[];};
+layout (binding = 1) writeonly buffer D {D_TYPE data_d[];};
+
+void main() {
+    const uint i = gl_GlobalInvocationID.z * 262144 + gl_GlobalInvocationID.y * 512 + gl_GlobalInvocationID.x;
+
+    if (i >= p.KX) {
+        return;
+    }
+    data_d[i] = D_TYPE(-float(data_a[i]));
+}