pmdomain: ti: Fix STANDBY handling of PER power domain

pmdomain: ti: Fix STANDBY handling of PER power domain

Per AM335x TRM[1](section 8.1.4.3 Power mode), in case of STANDBY,
PER domain should be ON. So, fix the PER power domain handling on standby.

[1] https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf

Signed-off-by: Sukrut Bellary <sbellary@baylibre.com>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Tested-by: Judith Mendez <jm@ti.com>
Link: https://lore.kernel.org/r/20250318230042.3138542-3-sbellary@baylibre.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>