pwm: axi-pwmgen: Rename 0x10 register

pwm: axi-pwmgen: Rename 0x10 register

Rename the 0x10 register from REG_CONFIG to REG_RSTN. Also rename the
associated bit macros accordingly.

While touching this, move the bit macros close to the register address
macro for better organization.

According to [1], the name of the 0x10 register is REG_RSTN, and there
is a different register named REG_CONFIG (0x18). So we should not be
using REG_CONFIG for the 0x10 register to avoid confusion.

[1]: http://analogdevicesinc.github.io/hdl/library/axi_pwm_gen/index.html

Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20241009-pwm-axi-pwmgen-enable-force_align-v1-1-5d6ad8cbf5b4@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>