rtc: mpfs: Remove printing of stray CR

During boot, the driver prints out a stray carriage return character.
Remove it, together with the preceding space character.

While at it, change prescaler to "unsigned long", as returned by
clk_get_rate(), to avoid truncating very large clock rates, and update
the format specifiers.

Fixes: 0b31d703 ("rtc: Add driver for Microchip PolarFire SoC")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/bce2ca405ef96b1363fd1370887409d9e8468422.1660659437.git.geert+renesas@glider.be