powervr: add firmware for Imagination Technologies BXS-4-64 GPU

Support for the BXS-4-64 GPU, as found in the TI AM68, has recently been merged into the
drm-misc-next tree [1][2]. This adds the initial firmware to support it.

[1] https://lore.kernel.org/all/20250410-sets-bxs-4-64-patch-v1-v6-0-eda620c5865f@imgtec.com/
[2] 81f6e0e0f3

Signed-off-by: Frank Binns <frank.binns@imgtec.com>

WHENCE

@@ -8294,6 +8294,9 @@ Driver: powervr - Imagination Technologies PowerVR graphics driver
 File: powervr/rogue_33.15.11.3_v1.fw
 Version: 1.0.OS@6503725
 
+File: powervr/rogue_36.53.104.796_v1.fw
+Version: 1.0.OS@6734358
+
 License: Redistributable. See LICENSE.powervr for details
 
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