panvk: bump maxPushConstantSize to 256

Vulkan 1.4 raises the minimum for maxPushConstantSize to 256, and given
that we intend on supporting 1.4 eventually and the change is very simple
might as well do it now.

Reviewed-by: Olivia Lee <olivia.lee@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35191>

src/panfrost/vulkan/panvk_cmd_push_constant.h

@@ -13,7 +13,7 @@
 struct panvk_cmd_buffer;
 struct panvk_shader;
 
-#define MAX_PUSH_CONSTANTS_SIZE 128
+#define MAX_PUSH_CONSTANTS_SIZE 256
 
 struct panvk_push_constant_state {
    uint64_t data[MAX_PUSH_CONSTANTS_SIZE / sizeof(uint64_t)];

src/panfrost/vulkan/panvk_physical_device.c

@@ -711,10 +711,13 @@ get_device_properties(const struct panvk_instance *instance,
        * descriptors, where the size is a 32-bit field.
        */
       .maxStorageBufferRange = UINT32_MAX,
-      /* 128 bytes of push constants, so we're aligned with the minimum Vulkan
-       * requirements.
+      /* Vulkan 1.4 minimum. We currently implement push constants in terms of
+       * FAUs so we're limited by how many user-defined FAUs the hardware
+       * offers, minus driver-internal needs. If we ever need go to higher,
+       * we'll have to implement push constants in terms of both FAUs and global
+       * loads.
        */
-      .maxPushConstantsSize = 128,
+      .maxPushConstantsSize = 256,
       /* On our kernel drivers we're limited by the available memory rather
        * than available allocations. This is better expressed through memory
        * properties and budget queries, and by returning