samples: Bluetooth: hci_uart_3wire: Align Kconfigs with hci_uart

Align Kconfig values used with bt-ll-sw-split Controller as
same used in hci_uart sample.

Relates to commit 2c6306d ("Bluetooth: Controller:
BT_CTLR_ISO_TX_BUFFER_SIZE from BT_ISO_TX_MTU")'.

Signed-off-by: Vinayak Kariappa Chettimada <[email protected]>

Author: cvinayak

samples/bluetooth/hci_uart_3wire/overlay-all-bt_ll_sw_split.conf

@@ -81,7 +81,7 @@ CONFIG_BT_CTLR_DF_CONN_CTE_REQ=y
 CONFIG_BT_CTLR_ADV_EXT=y
 CONFIG_BT_CTLR_ADV_PERIODIC=y
 CONFIG_BT_CTLR_ADV_ISO=y
-CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=251
+CONFIG_BT_CTLR_ADV_ISO_PDU_LEN_MAX=247
 CONFIG_BT_CTLR_ADV_ISO_STREAM_MAX=2
 
 # ISO Receive Controller
@@ -94,12 +94,12 @@ CONFIG_BT_CTLR_SYNC_ISO_STREAM_MAX=2
 # ISO Connection Oriented
 CONFIG_BT_CTLR_CENTRAL_ISO=y
 CONFIG_BT_CTLR_PERIPHERAL_ISO=y
-CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=251
+CONFIG_BT_CTLR_CONN_ISO_SDU_LEN_MAX=247
 CONFIG_BT_CTLR_CONN_ISO_PDU_LEN_MAX=251
 
 # ISO Transmissions
 CONFIG_BT_CTLR_ISO_TX_BUFFERS=8
-CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=251
+CONFIG_BT_CTLR_ISO_TX_BUFFER_SIZE=255
 CONFIG_BT_CTLR_ISOAL_SOURCES=2
 
 # ISO Receptions