Currently for Armv7 plaforms the quotient calculated in pl011
uart init code is moved to register r1.

This patch moves the quotient to register r2 as done for other
platforms in the udiv instruction. Value of register r2 is then
used to calculate the values for IBRD and FBRD register

Change-Id: Ie6622f9f0e6d634378b471df5d02823b492c8a24
Signed-off-by: Avinash Mehta <avinash.mehta@arm.com>