powerpc/configs/6xx: Drop no longer needed CONFIG_BT_HCIUART_H4

Since commit 943cc592 ("Bluetooth: bpa10x: Use h4_recv_buf helper
for frame reassembly") we no longer need to set CONFIG_BT_HCIUART_H4
in our defconfigs.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/configs/ppc6xx_defconfig

@@ -330,7 +330,6 @@ CONFIG_BT_BNEP_MC_FILTER=y
 CONFIG_BT_BNEP_PROTO_FILTER=y
 CONFIG_BT_HIDP=m
 CONFIG_BT_HCIUART=m
-CONFIG_BT_HCIUART_H4=y
 CONFIG_BT_HCIUART_BCSP=y
 CONFIG_BT_HCIUART_LL=y
 CONFIG_BT_HCIBCM203X=m