Rename microkernel-related types and structures

Use consistent naming for internal structures and related functions
- xnn_qs8_gemm_params -> xnn_qs8_conv_minmax_params
- xnn_qu8_gemm_params -> xnn_qu8_conv_minmax_params
- xnn_qs8_gemm_ukernel_function -> xnn_qs8_gemm_minmax_ukernel_function
- xnn_qu8_gemm_ukernel_function -> xnn_qu8_gemm_minmax_ukernel_function
- xnn_qs8_igemm_ukernel_function -> xnn_qs8_igemm_minmax_ukernel_function
- xnn_qu8_igemm_ukernel_function -> xnn_qu8_igemm_minmax_ukernel_function

PiperOrigin-RevId: 375629645
diff --git a/src/xnnpack/operator.h b/src/xnnpack/operator.h
index 0fcd216..11c77e5 100644
--- a/src/xnnpack/operator.h
+++ b/src/xnnpack/operator.h
@@ -276,7 +276,7 @@
       union xnn_f32_scaleminmax_params f32_scaleminmax;
     };
     union xnn_f32_chw_params f32_chw;
-    union xnn_qs8_gemm_params qs8_gemm;
+    union xnn_qs8_conv_minmax_params qs8_conv_minmax;
     // Average Pooling normally use qs8_avgpool_params, but also initialize qs8_gavgpool_params in case it needs to switch
     // to Global Average Pooling operation.
     struct {
@@ -289,7 +289,7 @@
       union xnn_qs8_add_params qs8_radd;
     };
     union xnn_qu8_add_params qu8_add;
-    union xnn_qu8_gemm_params qu8_gemm;
+    union xnn_qu8_conv_minmax_params qu8_conv_minmax;
     // Average Pooling normally use qu8_avgpool_params, but also initialize qu8_gavgpool_params in case it needs to switch
     // to Global Average Pooling operation.
     struct {