pwm: mediatek: always use bus clock for PWM on MT7622

According to MT7622 Reference Manual for Development Board v1.0 the PWM
unit found in the MT7622 SoC also comes with the PWM_CK_26M_SEL register
at offset 0x210 just like other modern MediaTek ARM64 SoCs.
And also MT7622 sets that register to 0x00000001 on reset which is
described as 'Select 26M fix CLK as BCLK' in the datasheet.
Hence set has_ck_26m_sel to true also for MT7622 which results in the
driver writing 0 to the PWM_CK_26M_SEL register which is described as
'Select bus CLK as BCLK'.

Fixes: 0c0ead76 ("pwm: mediatek: Always use bus clock")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/Y1iF2slvSblf6bYK@makrotopia.org


Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>