Correct prog_int64_t and prog_uint64_t typedefs

[sandeepmistry]

In avr/pgmspace.h: int32_t and uint32_t were used instead of int64_t and uint64_t

[ArduinoBot]

✅ Build completed.

⬇️ Build URL: http://downloads.arduino.cc/PR/samd/package_samd-b75_index.json

ℹ️ To test this build:

1. Open the Preferences of the Arduino IDE.
2. Add the Build URL above in the Additional Boards Manager URLs field, and click OK.
3. Open the Boards Manager (menu Tools->Board->Board Manager...)
4. Install Arduino SAMD core - Pull Request Correct prog_int64_t and prog_uint64_t typedefs #132
5. Select one of the boards under SAMD Pull Request Correct prog_int64_t and prog_uint64_t typedefs #132 in Tools->Board menu
6. Compile/Upload as usual