ARM: dts: at91: sam9x5: Fix the memory range assigned to the PMC

The memory range assigned to the PMC (Power Management Controller) was
not including the PMC_PCR register which are used to control peripheral
clocks.

This was working fine thanks to the page granularity of ioremap(), but
started to fail when we switched to syscon/regmap, because regmap is
making sure that all accesses are falling into the reserved range.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reported-by: Richard Genoud <richard.genoud@gmail.com>
Tested-by: Richard Genoud <richard.genoud@gmail.com>
Fixes: 863a81c3be1d ("clk: at91: make use of syscon to share PMC registers in several drivers")
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>