ARM: OMAP1: clock: Fix UART rate reporting algorithm

[ Upstream commit 338d5d476cde853dfd97378d20496baabc2ce3c0 ]

Since its introduction to the mainline kernel, omap1_uart_recalc() helper
makes incorrect use of clk->enable_bit as a ready to use bitmap mask while
it only provides the bit number.  Fix it.

Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>