arm64: dts: ti: k3-am62p: Fix supported hardware for 1GHz OPP

The 1GHz OPP is supported on speed grade "O" as well according to the
device datasheet [0], so fix the opp-supported-hw property to support
this speed grade for 1GHz OPP.

[0] https://www.ti.com/lit/gpn/am62p


Fixes: 76d855f0 ("arm64: dts: ti: k3-am62p: add opp frequencies")
Cc: stable@vger.kernel.org
Signed-off-by: Judith Mendez <jm@ti.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>