phy: Group vendor specific phy drivers

Adding vendor specific directories in phy to group
phy drivers under their respective vendor umbrella.

Also updated the MAINTAINERS file to reflect the correct
directory structure for phy drivers.

Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Kishon Vijay Abraham I <kishon@ti.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-arm-msm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-omap@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-rockchip@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>