[ARM] 3899/1: Fix the normalization of the denormal double precision number.

The significand should be shifted until the value of bit [62] is 1
to normalize the denormal double number.

Signed-off-by: Takashi Ohmasa <ohmasa.takashi@jp.panasonic.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>