[PATCHv2 4/4] pwm: ftm-pwm: Add big-endian support

This add the big endianness support for the FTM PWM driver, which will run on LS1 SoC. Now for the following scenarios: SoC | CPU | FTM-PWM | 'big-endian' property is needed? -||-|- Vybird | LE| LE| No LS1 | LE

[PATCHv2 4/4] pwm: ftm-pwm: Add big-endian support

This add the big endianness support for the FTM PWM driver, which will run on LS1 SoC. Now for the following scenarios: SoC | CPU | FTM-PWM | 'big-endian' property is needed? -||-|- Vybird | LE| LE| No LS1 | LE