eeprom: at25: add support for Infineon Cypress QSN FRAMs

eeprom: at25: add support for Infineon Cypress QSN FRAMs

Add support for Infineon Cypress CY15****QSN FRAM chips.
Unlike the QN variants these chips have an 8 byte JEDEC ID.

The layout of the serial number matches that of already supported chips
like the CY15B204QN, so make the read-out unconditional.

Tested with the CY15B204QSN. According to Infineon datasheets, all QSN
variants appear to share a consistent pattern so the size should be
correctly detected based on the density bits in the ID:

CY15B201QSN: 0x00 00 00 00 06 82 54 40, density_id:  8: 1Mb
CY15B102QSN: 0x00 00 00 00 06 82 51 48, density_id:  9: 2Mb
CY15B204QSN: 0x00 00 00 00 06 82 54 50, density_id: 10: 4Mb
CY15V108QSN: 0x00 00 00 00 06 82 52 58, density_id: 11: 8Mb

Signed-off-by: Patrick Wicki <patrick.wicki@siemens.com>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Tested-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Link: https://patch.msgid.link/20260120130603.1066559-1-patrick@subset.ch
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>