This commit makes it so that MICROPY_PY_MACHINE_PWM is enabled if at least
one of MICROPY_PY_MACHINE_HW_PWM and/or MICROPY_PY_MACHINE_SOFT_PWM are
enabled. This simplifies the configuration for boards, and fixes DVK_BL652
which enabled PWM without selecting software or hardware implementations.
With this change, DVK_BL652 and EVK_NINA_B1 now enable (hardware) PWM.
Signed-off-by: Damien George <damien@micropython.org>