ARM: 7304/1: ioremap: fix boundary check when reusing static mapping

ARM: 7304/1: ioremap: fix boundary check when reusing static mapping

Since commit e4053c391ddf6680112adc0fd6cbb1b8d8df813b "ARM: add
generic ioremap optimization by reusing static mappings" ioremap()
is trying to reuse existing static mapping when possible.

The condition checking boundaries of the requested and existing
mappings didn't take in-page offset into consideration though,
which lead to obscure and hard to debug problems when requested
mapping crossed end of the static one.

Signed-off-by: Pawel Moll <pawel.moll@arm.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>