Topology2: fix obs size for src converter from 48k

From 48k input, the obs for 11025/22050/44100/88200/176400 setting
need take care, previous implementation left 5 words redundancy
for output, this change removed redundancy, since actual output
buffer size always use double obs size.

Signed-off-by: Baofeng Tian <[email protected]>

tools/topology/topology2/include/components/src_format_s32_convert_from_48k.conf

@@ -27,7 +27,8 @@
 					]
 					out_bit_depth [ 32 ]
 					out_valid_bit_depth [ 32 ]
-					obs "$[($out_channels * (($[($out_rate + 999)] / 1000) + 4)) * ($out_bit_depth / 8)]"
+					# actual buffer size in sof is obs * 2, so here simply set to its period size
+					obs "$[$out_channels * ($out_bit_depth / 8) * (($out_rate / 1000)) * ($period / 1000)]"
 				}
 			]