You will not get 120KHz - the closest is 125KHz. Assuming a clock of 8MHz, this will give you 125KHz on CCP1 (RC2) with a PIC1F877A.

Code:
TRISC = 0  'PORTC all outputs
PR2 = 15  'Load Period Register
CCPR1L = 8  'Set 50% duty cycle
CCP1CON = %1100  'PWM mode
T2CON.2 = 1  'Start TIMER2