GR Lynchee does not support bootloader

[teetak01]

Building project mbed-os-example-pelion-GR_LYCHEE-ARM-TCP (GR_LYCHEE, ARMC6)
Scan: mbed-os-example-pelion
Using ROM regions bootloader, header, application in this build.
  Region bootloader: size 0xc000, offset 0x18000000
  Region header: size 0x70, offset 0x18010000
  Region application: size 0x7efc00, offset 0x18010400
Configuration error: Bootloader not supported on this target. RAM start not found in targets.json.

[JanneKiiskila]

The bootloader support is in place, but unfortunately only in the Mbed OS master at this stage.
@adbridge @0xc0170 - we need the Mbed OS 5.15.1 patch release with those changes included.

• RZ_A1H and GR_LYCHEE: Enable bootloader support mbed-os#12223

[ciarmcom]

Internal Jira reference: https://jira.arm.com/browse/IOTPART-9035

[JanneKiiskila]

Seem the changes did not make Mbed OS 5.15.1.

[teetak01]

Fixed as part of Mbed OS 5.15.2

#127