Remove rom start/size macros when bootloader=true

Allow the application to specify this depending on whether/how
it is using the bootloader and whether it requires a CM0+ image.

Author: hennadiykytsun

targets/targets.json

@@ -8609,8 +8609,6 @@
             "function": "PSOC6Code.complete"
         },
         "bootloader_supported": true,
-        "mbed_rom_start": "0x10000000",
-        "mbed_rom_size": "0x100000",
         "sectors": [[268435456, 512]],
         "overrides": {
             "network-default-interface-type": "WIFI"
@@ -8624,8 +8622,6 @@
             "function": "PSOC6Code.complete"
         },
         "bootloader_supported": true,
-        "mbed_rom_start": "0x10000000",
-        "mbed_rom_size": "0x200000",
         "sectors": [[268435456, 512]]
     },
     "CY8CKIT_062S2_43012": {