clk: ast2600: BCLK comes from EPLL

clk: ast2600: BCLK comes from EPLL

[ Upstream commit ac8156b1e0d4d940278f7ce145acd9503f3bf219 ]

This correction was made in the u-boot SDK recently. There are no
in-tree users of this clock so the impact is minimal.

Fixes: 9ea7cc96411f ("clk: Add support for AST2600 SoC")
Link: https://github.com/AspeedTech-BMC/u-boot/commit/8ad54a5ae15f27fea5e894cc2539a20d90019717
Signed-off-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20220421040426.171256-1-joel@jms.id.au
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>