SW_BAND frequencies should be displayed with MHz (not kHz)

[Allan-N]

Describe the bug
If I select the 40 meter band and tune the radio to 7.150 the display shows kHz. This should be MHz

To Reproduce
Tune the radio to any if the SW_BAND frequencies and observe the display.

Expected behavior
The frequencies (7.xxx, 14.xxx, etc) are MHz.

Additional information

• Arduino IDE, version 2.3.2
• SI473X_ALL_IN_ONE_OLED_RDS_CHINESE_V8r and SI473X_ALL_IN_ONE_OLED_RDS_CHINESE_V9
• ATS-20+ w/Arduino Nano