i2c: mux: Generate longer i2c mux name

i2c: mux: Generate longer i2c mux name

For !DM case busses are listed as
ZynqMP> i2c bus
Bus 0:	zynq_0
Bus 1:	zynq_0->PCA9544A@0x75:0
Bus 2:	zynq_0->PCA9544A@0x75:1
Bus 3:	zynq_0->PCA9544A@0x75:2
Bus 4:	zynq_1
Bus 5:	zynq_1->PCA9548@0x74:0
Bus 6:	zynq_1->PCA9548@0x74:1
Bus 7:	zynq_1->PCA9548@0x74:2
Bus 8:	zynq_1->PCA9548@0x74:3
Bus 9:	zynq_1->PCA9548@0x74:4
Bus 10:	zynq_1->PCA9548@0x75:0
Bus 11:	zynq_1->PCA9548@0x75:1
Bus 12:	zynq_1->PCA9548@0x75:2
Bus 13:	zynq_1->PCA9548@0x75:3
Bus 14:	zynq_1->PCA9548@0x75:4
Bus 15:	zynq_1->PCA9548@0x75:5
Bus 16:	zynq_1->PCA9548@0x75:6
Bus 17:	zynq_1->PCA9548@0x75:7

where is exactly describing i2c bus topology.
By moving to DM case i2c mux buses are using names from DT and because
i2c-muxes describing sub busses with the same names like i2c@0, etc it
is hard to identify which bus is where.
Linux is adding topology information to i2c-mux busses to identify them
better.
This patch is doing the same and composing bus name with topology
information.

When patch is applied with topology information on zcu102-revA.
ZynqMP> i2c bus
Bus 0:	i2c@ff020000
   20: gpio@20, offset len 1, flags 0
   21: gpio@21, offset len 1, flags 0
   75: i2c-mux@75, offset len 1, flags 0
Bus 2:	i2c@ff020000->i2c-mux@75->i2c@0
Bus 3:	i2c@ff020000->i2c-mux@75->i2c@1
Bus 4:	i2c@ff020000->i2c-mux@75->i2c@2
Bus 1:	i2c@ff030000  (active 1)
   74: i2c-mux@74, offset len 1, flags 0
   75: i2c-mux@75, offset len 1, flags 0
Bus 5:	i2c@ff030000->i2c-mux@74->i2c@0  (active 5)
   54: eeprom@54, offset len 1, flags 0
Bus 6:	i2c@ff030000->i2c-mux@74->i2c@1
Bus 7:	i2c@ff030000->i2c-mux@74->i2c@2
Bus 8:	i2c@ff030000->i2c-mux@74->i2c@3
Bus 9:	i2c@ff030000->i2c-mux@74->i2c@4
Bus 10:	i2c@ff030000->i2c-mux@75->i2c@0
Bus 11:	i2c@ff030000->i2c-mux@75->i2c@1
Bus 12:	i2c@ff030000->i2c-mux@75->i2c@2
Bus 13:	i2c@ff030000->i2c-mux@75->i2c@3
Bus 14:	i2c@ff030000->i2c-mux@75->i2c@4
Bus 15:	i2c@ff030000->i2c-mux@75->i2c@5
Bus 16:	i2c@ff030000->i2c-mux@75->i2c@6
Bus 17:	i2c@ff030000->i2c-mux@75->i2c@7

Behavior before the patch is applied.
ZynqMP> i2c bus
Bus 0:	i2c@ff020000
   20: gpio@20, offset len 1, flags 0
   21: gpio@21, offset len 1, flags 0
   75: i2c-mux@75, offset len 1, flags 0
Bus 2:	i2c@0
Bus 3:	i2c@1
Bus 4:	i2c@2
Bus 1:	i2c@ff030000  (active 1)
   74: i2c-mux@74, offset len 1, flags 0
   75: i2c-mux@75, offset len 1, flags 0
Bus 5:	i2c@0  (active 5)
   54: eeprom@54, offset len 1, flags 0
Bus 6:	i2c@1
Bus 7:	i2c@2
Bus 8:	i2c@3
Bus 9:	i2c@4
Bus 10:	i2c@0
Bus 11:	i2c@1
Bus 12:	i2c@2
Bus 13:	i2c@3
Bus 14:	i2c@4
Bus 15:	i2c@5
Bus 16:	i2c@6
Bus 17:	i2c@7

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Heiko Schocher <hs@denx.de>