mtd: spi: nor: force mtd name to "nor%d"

mtd: spi: nor: force mtd name to "nor%d"

Force the mtd name of spi-nor to "nor" + the driver sequence number:
"nor0", "nor1"... beginning after the existing nor devices.

This patch is coherent with existing "nand" and "spi-nand"
mtd device names.

When CFI MTD NOR device are supported, the spi-nor index is chosen after
the last CFI device defined by CONFIG_SYS_MAX_FLASH_BANKS.

When CONFIG_SYS_MAX_FLASH_BANKS_DETECT is activated, this config
is replaced by to cfi_flash_num_flash_banks in the include file
mtd/cfi_flash.h.

This generic name "nor%d" can be use to identify the mtd spi-nor device
without knowing the real device name or the DT path of the device,
used with API get_mtd_device_nm() and is used in mtdparts command.

This patch also avoids issue when the same NOR device is present 2 times,
for example on STM32MP15F-EV1:

STM32MP> mtd list
SF: Detected mx66l51235l with page size 256 Bytes, erase size 64 KiB, \
total 64 MiB

List of MTD devices:
* nand0
  - type: NAND flash
  - block size: 0x40000 bytes
  - min I/O: 0x1000 bytes
  - OOB size: 224 bytes
  - OOB available: 118 bytes
  - ECC strength: 8 bits
  - ECC step size: 512 bytes
  - bitflip threshold: 6 bits
  - 0x000000000000-0x000040000000 : "nand0"
* mx66l51235l
  - device: mx66l51235l@0
  - parent: spi@58003000
  - driver: jedec_spi_nor
  - path: /soc/spi@58003000/mx66l51235l@0
  - type: NOR flash
  - block size: 0x10000 bytes
  - min I/O: 0x1 bytes
  - 0x000000000000-0x000004000000 : "mx66l51235l"
* mx66l51235l
  - device: mx66l51235l@1
  - parent: spi@58003000
  - driver: jedec_spi_nor
  - path: /soc/spi@58003000/mx66l51235l@1
  - type: NOR flash
  - block size: 0x10000 bytes
  - min I/O: 0x1 bytes
  - 0x000000000000-0x000004000000 : "mx66l51235l"

The same mtd name "mx66l51235l" identify the 2 instances
mx66l51235l@0 and mx66l51235l@1.

This patch fixes a ST32CubeProgrammer / stm32prog command issue
with nor0 target on STM32MP157C-EV1 board introduced by
commit e17dc9227c70 ("mtd: spi-nor: allow registering multiple MTDs when
DM is enabled").

Fixes: e17dc9227c70 ("mtd: spi-nor: allow registering multiple MTDs when DM is enabled")
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
[trini: Add <dm/device.h> to <mtd.h> for DM_MAX_SEQ_STR]
Signed-off-by: Tom Rini <trini@konsulko.com>